FREE - In Google Play
FREE - in Win Phone Store
New version is now available for Android Alfil 13. Incorporates the new version of Alfil, with many improvements. Soon will both version for 32-bit and 64-bit. This version for Android brings several features such as voice announcement of the plays, and I’m working on a new voice recognition system to be able to say the plays voice engine.
The version 13 for Android will be sent free of charge to anyone who link or advertise in any forum or program page. Just send me an email with the link where it is bound, even a forum and send you the free program.The price of this is to cover the cost of the project Alfilchess free.
There is a new Android chess app: Senior Chess. Has anyone tried it?
Thanks a lot, DarkJediNinja. It is just a matter of time, many hours of testing. After many years I can ususally "feel" the level of the program at a glance, so I focus on a few best, say twenty, and have a general idea of the rest. During the last months have appeared in Android many learning ones: tactics, strategy, courses...etc.
Best new ones to come are Hiarcs, Houdini and Komodo 5. I am beta-tester of many of the best, so I can know in advance their pros and against. I am preparing a huge article showing them all.
Today the best chess apps on Android for me are:
DroidFish 1.45, Shredder 1.2.2, ChessGenius 2.5.0, Mobialia, Chess ( jwtc), CFA, Ches.com, Rival Chess, Chess Game, Dark Knight, AMobile Chess, Chessbae on line, Playchess, Chess at ICC, Scid on the go and SimpleChess. The three apps refered above will come during next months, and there are around fifty apps concerning learning, practice and courses, that I will explain in my long article .
Apps concerning chess in Android now we have more than two thousand, amazing. If you dont have any selection criteria it would be impossible just to see them and I see them ALL at least every week.
Regards, and thanks again.
After reading your answer, I thought: "This guy seems to know as much about Computer Chess as Amador Cuesta, the well respected Spanish expert on this subject. And he's a fan of Android and has a Nexus Tablet as Amador does. And he's Spanish. And yet another coincidence: his name on his profile is Amy Quest that sounds pretty similar.". Well, there is no need to be a chess genius to find out that you are really Amador Cuesta, although I had doubted because your style in English is more "polite" than the direct and "politically incorrect" style that you use in Spanish.
I really enjoy your column in Doble Jaque (spanish podcast on chess) as well as the rest of the podcast. Please send my regards to Yago, Carlos and Vicente.
I will be waiting anxiously for the new article that you mentioned about chess learning tools on Android.
One category that I didn't see you mention is apps for Chess Notation of games during tournaments.
My computing devices are a bit eclectic: Windows 7 notebook with i7 processor, Ipad2 tablet with iOS6 and Samgung Galaxy S3 smartphone with Android ICS.
In the Galaxy S3 I have installed DroidFish 1.45 (following your advice), Mobialia 4.2.5 , Scid on the Go, Chess.com app, ChessBase online, Reloj de Ajedrez, Chess Book Study, Chess Opener and yNotate.
In my notebook I have Arena with a couple of engines, Scid and some other programs.
But the main platform that I use for playing chess is my iPad. I know you're a fan of Android and I hope you'll forgive me for loving my iPad. I owe it having returned to the pleasure of playing chess.
In all of my devices I have Kindle (Amazon ebook reader app) to read my chess books. In my iPad I also have e+books, a great app for reading chess books but their library is still a bit small. And there is no Android version yet.
Main use of my mobile devices related to chess, in descending order of usage:
1) Play online live chess against human oponents (chess.com app)
2) Practice tactics (chess.com app with premium membership and chessimo app for iPad)
3) Listen to podcast while I drive (mainly chess podcasts like Doble Jaque and The Full English Breakfast)
4) Read chess ebooks (Kindle, e+books)
5) Try to improve my openings (Chessbase online, Chess Openings Pro)
6) Use it as a chess board or chess clock when playing against a casual oponent (Shredder for iPad o Reloj de Ajedrez)
7) Playing against the computer (many different apps). It's curious but playing against the computer is one of the things i do less frequently. I prefer to play against a human being and I'm grateful I have discovered chess.com as no friend or relative of mine wanted to play chess against me.
8) Analyze games: This is an area in which I have yet to choose my tools and start using it a lot. So far, most of my games are in chess.com and I use their computer analysis service but it's no as good as some of the available mobile platforms.
By the way, I'm an IT guy (I work as IT Director for a well known Spanish Security company), a chess fan and a mediocre chess player. Good use of computing in chess is a topic that always interested me a lot.
So, I appreciate your work (and envy you a little bit).
Best regards, Fernando (DarkJediNinja)
Best Android / IOS Chess Apps 2012-2013 . Facts, Figures and Trends
Yes, Fernando, you´re right, it´s me. Thanks a lot for your kind words and congratulations for your shrewdness.
I am more polite in English because the chess.com readers don´t know about our specific problems and situation in Spain. Obviously here I have ( or at least try ) to express my ideas on a global basis, nor on a local one, impossible to understand for the rest.
Of course I will give your regards to Yago and Carlos. Our next radio program/podcast will take place today.
Reading your impressive answer, there is very few I can tell you about computer chess, software or mobile devices.
Your computing devices are pretty good, although my list is just a bit longer.
My monster PC is an improved Skulltrail platform operating on twelve(12) cores /24 threads, with 256 DDR3 GB of Ram, six TB of HD with nearly two (2) TB for the Nalimov TBs.
It incorporates the last and strongest chess software today: Houdini 3, Critter 1.6a ( fantastic), Rybka 4, Stockfish 2.3.1, Ivanhoe 9.46 H, Komodo 5 ( SC waiting for both the Android and MP versions), Strelka 5.5, Naum 4.2 ( already dissapeared), Chiron 1.1a, Hiarcs Chess Explorer 1.2 ( World software Champion, this new version just released), Deep Fritz 13 , Deep Junior 13.3( World absolute Champion), Leopard 0.7c ( incredibly strong and nearly unknown) or Spike 1.4 Leiden , among others.
My mobile Android devices list is rather longer just now : Galaxy SIII, Galaxy Note II, Google Nexus 7, Asus Transformer Prime and Asus Padfone 2 . Not bad.
You have to add to your Galaxy SIII some programs from the list I gave you yesterday in my answer, starting with Playchess.com, a MUST.
I have nothing to forgive you, I respect very much all the Apple products, although I don´t agree with their strategies. It is a matter of opinion, nothing else.
We have created in Spain a group of chess mobile devices testers/users, around twelve, getting a complete scope with more than forty devices, many of them Apple : Galaxy S, SII, SIII, Galaxy Note / Note II, HTC One X / X+, iPhone 3/4/4S and 5, iPad /2/3 and 4, several LG and Huawei SFs, Asus Transformer Prime, Asus Transformer Infinity and just opening the box of the new Asus Padfone 2, after several weeks testing Galaxy Note 10.1/ Tab 2 and Nexus 7 tablets.
We will get also next week both Nexus 4 and 10, the two new Google marvels.
In terms of software preferences ( playing programs), these are MY favorites TODAY:
DroidFish 1.45 : the best , more complete and strongest Android chess app today ,by far, with the Critter 1.6a ( absolutely impressive) and Stockfish 2.3.1 as favorite engines. Very complete, extremely strong, easy to use, MP and UCI capabilities, wide opening book options, Gaviota endgame TBs,,,,it got EVERYTHING.
Go to Aart Bik´s and Peter Österlund ´s webs to get the main Android UCI engines ( Robbolito, GnuChess, Ivanhoe,several Stockfish versions and many others), and Polyglot opening books respectively ( you can get .ctg opening books everywhere, starting with the best one, the Hiarcs 14cBook ).
Shredder 1.2.2 : it incorporates a fantastic GUI , but needs a complete update ( engine and features) and MP capability. Very strong. Sixteen World titles support it. “Cazi ná”, as we say in Spanish.
ChessGenius 2.5.0 : my best option for general public, by far. Strong and very easy to handle. Rocky and unique human-like style..., and ten World titles behind it.
Hope to see its new version soon, as in IOS ( v. 3.1 ).
Mobialia : a LOT of improvements during last year. Very funny and complete.
Chess Game and AMobile Chess : former DroidFish versions, very strong.
Dark Knight : DroidFish version for Android 3.0, one of my favorites.
Chess ( jwtc.nl), Chess for Android, Scid on the Go and Rival Chess, are four different programs/platforms I use on a mix basis, for different things.
Chessbase Online, another must, next version will include an analysis engine for the nearly six million games to check.
We are ALL waiting for three new apps that shall lead the chess Android market in the near future: Houdini , Hiarcs and Komodo 5. I am beta-tester of one of them, and we all hope they will be delivered soon.
For IOS O.S., you have minimum options compared with Android ( nearly 2,700 items related to chess now), but with some important exceptions:
- You are very lucky and already got the Hiarcs version. Congratulations. For me it is THE reference program in terms of playing style , evaluation function and exceptional features . Hope the Android version ( very strong) will come soon.
- The same situation is given with Komodo 4, as there is a version for IOS and only the 3 for Android. The former is called Chess Legends ( v. 1.2) by Schogini Sysyems. I hope this will be solved with the version 5 for both.
- You also got the Stockfish 2.4 program ( the IOS DroidFish “counterpart”, but not so complete), extremely strong and with MP capabilities.
- And IOS got its Chessimo version, probably the best chess learning app for mobile devices in the market just now. I contacted them and told me the Android version is not yet considered ( a great mistake, in my opinion, and a rather strange decision for being Germans).
This is my IOS playing program list and chess items ( non-exhaustive) in order of preference:
- Hiarcs Chess ( v. 13.31), by far the best chess program in this O.S. THE reference.
- Stockfish Chess ( v. 2.4). Extremely strong, great ending player and MP.
- Shredder Chess. Amazing GUI.
- ChessGenius. New 3.1 version. My number one for general public.
- Fritz Chess. A legend, now on IOS.
- Chessbase Online and Playchess.com. Two MUST.
- Chessimo. Mentioned above. The chess learning reference here. A must.
- Chess Academy for Kids. Useful tool for children.
- Chess at ICC and Chess with Friends, both for playing in the web, but there are others.
- A final group of second- line contenders : Chess DB HD, tChess Pro, Ichess Pack HD, Chess problems, Chess Classic, Deep Green and Chess Clock.
As their names point out, different apps for different uses.
Now I will answer your main chess related items in order:
Main Android Chess Apps:
1) There are TOO MANY playing online webs and only a few ones are really worthy : Playchess, Chess at ICC, FICS, Chess.com, SimpleChess, Chess Instant, ChessOK Playing Zone, ChessCube, Jaque Mate, Sala Online InterAjedrez and Buho 21 are the usual ones I try.
In Google Play you have more than fifty apps for playing in the web. As this is a personal choice, just have a look on them, read the user´s opinions , and download and try the most interesting ones for you , playing and drawing your own conclusions, as with the rest of chess apps in Google Play (or in Apple Store).
I can mention you at a glance a few of them:Chess Online ( two different apps with the same name), Chess by Post, Chess Time, ChessPresso, Ajedrez Chess Live, Chess with Devices, Free Online Chess, ChessWorld.net, Ajedrez Online, Chess Time, onChess, Yafi...etc.
2) For practicing tactics you have new and interesting apps: Tapchess/Tactics Vol. I, Chess Puzzler, Idea Tactics, Tactic Trainer, Daily Chess Puzzles, Chess Puzzles , iChess Tactics, ChessDiags and Chess Mates.
- For learning/studying you have : Chess Opener and Chess Openings ( Openings), Chess Book Study and Chess Guide , Medio Juego Chess ( Middle Game), Master Strategy and Chess Strategy Guide ( Strategy), and for beginners , as the name points out, Learn chess for beginners.
Most of them are free but a few are not, so you have to read carefully the opinions and users valuations BEFORE buying it, although you have a while to get your money back. It is difficult to assess all of them , as it depends on each personal profiles, uses, needs and tastes.
- There are several apps that I use just for fun or as useful tools for playing, learning, reading, inform and/or studying chess: MiniChess ( very funny , just a playing chessboard of 5X5 ), Chess Book Study, Analyze This ( for dual engine analyzing positions, interesting), Chess PGN, CBH to PGN and Chess PGN Viewer / Helper ( all extremely useful),YNotate ( for chess notation recording), ChessLetter, David Kaufmann Chess Web, Chess News ( all of them for reading chess news), Chess Engines, C4A, Chess 9, Chess Tips, Z-Chess-101, Genesis Chess, Elite, Chess Walk , Chess Master,Alfil and Chess Live ( just for playing and fun at another level), Chess 960 Generator ( Fischer Random), Chess Trivia, 8 Queens Puzzle ( several different apps), Knights & Queens ( Knight tour + 8 Queens puzzle),Chess Champions ( brief players reviews), Curiosidades del ajedrez ( Chess curiosities, in Spanish), Chess Glossary ( very useful and interesting), Android Chess Timer ( one of the several chess clocks available in GP), Chess History and Reminiscence, History of Chess, Today in Chess History ( all of them chess history, at different levels), and Chess Players Database ( not so complete as it seems).
- Although there are some trials for getting a chess talking app - for blind people mainly- ( Voice Chess and others with Siri and Sherpa soft), there is still a LOT of work to do, as they still don´t work properly. As everything in life, many working hours still ahead.
3)For e-books I use mainly Kindle and PDF Android Viewer, among others. I got three thousand chess e-books and I don´t have any problem using them.
4) For improving openings I mentioned some apps above, although the best option is playing against good engines, using adjusted and updated opening books, as the Hiarcs 14cBook.
5) An interesting idea to use a tablet- on my new Padfone 2 is pretty good- as a chessboard, but I just prefer 3D figures to do this. J)
6) If you get used to play against an engine ( e.g. Hiarcs), you will be able to crush any human contender. Chess is a matter of practice and study, and to be able to get in your pocket a powerful tool, stronger than any human player, is a good option, at least for me.
7) For analyzing games , I usually try DroidFish 1.45 with its different engines .
Very soon we will have on Android Chessbase Online incorporating an engine ( may be Fritz or Houdini) and Hiarcs . Not bad at all.
Now the forthcoming trends 2012-2013 ( and beyond):
During 2013 there will be several crucial milestones concerning the mobile devices market, that obviously shall affect us all, including chess users:
- The appearance of Windows 8 / 8 RT, both for X86 and ARM micros, with the impact and all the consequences it will have in the future ( Windows 8 Phone et al).
- The also crucial appearance of the new ARM Cortex A15 micro, A9 successor and next ARM generation for 2013. The first units of this new micro are both the new Qualcomm Snapdragon S4 Pro (Krait) quad- core micro, now on several smartphones, and the Samsung Exynos 5250 ( the first REAL A15 in the market) dual-core micro operating in the new Nexus 10 tablet . Some future
A15 examples: Nvidia Tegra 4 ( Wayne), Samsung Exynos 5 (Adonis) family,
TI OMAP 5, Qualcomm S4 Pro ( Krait) and successors, Hisilicom ( Huawei)
K3V3, A6X and its successors, as contenders of the new Intel Atom family
( Medfield / Clover Trail) and Intel i3/i5/i7 Ivy Bridge.
- The third milestone ( the last but not the least) will be even more crucial for Android: a huge jump , transforming Android from a 32 bits O.S. into a new 64 bits one. This will be THE real big change, as v7-32 bits architecture will be replaced by the new v8-64 bits one.” Cazi ná “( again). Working together and establishing joint synergies, the A15 micros ( and their successors) with v8 architecture, will create little monsters , mobile devices ( and strong chess tools , around 3.000 Elo points) so powerful that are just impossible to imagine today.
- There is also for me a fourth very important item. There is a growing tendency into the mobile market towards the mixed tablets/ PCs ( or sliding hybrid ultrabooks as Sony people say), a two-in-one Asus idea developed nearly two years ago ( Transformer family), which everybody is copying now, as will happen with the Padfone ( smartphone + tablet in one). The tablet integrates into a dockstation which includes a physical keyboard, extra battery, SD card , USB and other connection slots...etc.
For me, Asus is number one in I+D. It is the grand “covered” manufacturer in
the world, but not very known in market by general public, incredibly and
unfortunately. They get the ideas and the rest copy them. May be a question of
strategies , but the brand image is not as good as it might be, in my opinion.
The sales boom into the mobile segment ( smartphones and tablets), is
decreasing dramatically the ultrabooks , notebooks , netbooks and PC market
sales, all of them in free fall now, above all the last one. Hard 2013 prospects
for all of them.
Some of the new hybrid tablets for 2013: Microsoft Surface ( family), Samsung
ATIV ( family), Asus Vivo and Transformer Book, Sony Vaio DUO 11, or Dell
XPS Duo 12, among others.
My great favorite for next year ( my next acquisition) will be for sure the Asus
Transformer Book. I already tested a sample and got astonished with the results.
Amazing specs: Intel i7 ( 3517U )micro at 3 GHz, 4 GB of DDR3 memory, 628
GB ( 500 SATA + 128 MSSD), Windows 8 ( 64 bits) O.S., and 13.3” display.
Just a dream, untill you have to pay for it: 1.500 Euros, but if you want a marvel,
you have to pay for it. As we say here: “ nobody gives Euros at cents”, or
“bargains usually become very expensive“.
Be very careful with the “offers”, “savings” and sales in unusual places/ways, and on Internet even more. Electronic devices have to have “name and face”. I have been buying my computers in the same places to the same people ( Iñaqui from Check Computers and Patricia from Mundo PDA) during nearly fifteen years.
We know each other very well, warranty is guaranteed ( “valga la redundancia” as we say in Spanish), and if any problem arises, no matter the kind, it is solved at once.
My personal mobile devices ( Android / IOS ) list of favorites for 2012-2013:
Asus Padfone 2
Google Nexus 4
HTC Droid DNA ( Verizon customers) / J Butterfly ( Japanese market)
LG Optimus G Sprint
Samsung Galaxy SIII
HTC One X+
iPhone 4S / 5
The first four ones incorporate the Krait micro, so in terms of calculation power ( for chess) , they are the best ones for me. Unfortunatelly we will not see most of the fantastic Chinese products in Europe, due to their dubious sales channels strategies , at least in Spain. New Nexus family ( 4, 7 and 10) has shaked this highly competitive segment, above all with their prices. There are too many contenders here,with the addition of Google or the “coming back” of HTC and LG. So next year the competence will be ruthless, as they will have to include- to maintain 2012 prices- bigger displays ( 5” or more), powerful micros ( A15 quad-core at 2-2.5 GHz), 3,000 mAh batteries, 3 GB/128 RAM/internal memories, 12 Mpixels ( or more) in camera, better connectivity...etc.
Market is getting crazy during 2013, as device-generation- time will diminish from one year to six months, and neither economy nor us are prepared for that.
The “Smartphones War” is going on and shall intensify much more day after day.
Samsung Galaxy Note II
HTC J Butterfly / HTC Droid DNA
OPPO Find 5
LG Optimus Vu II
Sony C650X Odin
The last three projects are supposed to come out during next year, and all of them are between 5 and six inches ( display). HTC and OPPO incorporate Krait micros, but the Galaxy Note II continues being the reference in this segment today.
Google Nexus 10
Samsung Galaxy Note 10.1
Apple iPad 4
Samsung Galaxy Tab 2
A tremendous fight in this segment. All of them are fantastic products and the market share will be crucial. This pie is huge and everybody wants to participate.
Google Nexus 7
Acer Iconia Tab A110
Apple iPad Mini
Huawei Media Pad
Amazon Kindle Fire HD
Fierce and even more terrific rivalry in the segment of the so called “low cost” tablets. Nexus 7 has got up the bar very high. Next year will see a revolution here, as the potential market in this segment is gargantuan.
There are rumors of a coming Samsung Galaxy Note with 7”, but today just rumors, as many others, like the ones about the future Galaxy S IV ( 5”, Exynos 5400 Adonis (A15) micro at 2 GHz, 3 GB of RAM, 3.000 mAh battery...etc).
Other tablets are at another level, in my opinion: Nook family, Ainol Novo 7 Aurora II, BQ Maxwell Plus, NEC MediaTab UL N08-D, Sharp Aquos Pad SHT21 or both Lenovo IdeaTab A2107 / 2110, many of them still to arrive.
Next year will bring incredible novelties, bigger displays, much stronger micros ( A15), 64 bits ( v8) Android architecture, Windows for ARM micros, more RAM ( 3 GB), better connectivity, more powerful batteries...etc. But as we say in Spanish, we will cross that bridge when we arrive to it, or as my mother used to say: “ no te adelantes como los de Pozas”.
Wait and see, like everything in life ( “tiempo al tiempo” in Spanish).
Search, compare and choose the best option for YOU.
Enough for today. Best regards to everbody.
Can you fix and and upgrade the pre move button on chess apk cause at the deeper end you're surely lose :(
that isn't to hard i hope, cmon please do it fast :)
Thanks a lot, Fernando. Read my new article : " Facts, figures and Trends" for 2012-2013.
Chess All Engines is another GUI for Android. A very good program with a lot of engines. If you are bored because you always play against StockFish there is the google play link:
You are RIGHT, Pitimol.
Can any1 help me out in finding the strongest Chess App for android??
Read the very complete Post of Alex541 in this same thread. Droidfish seems to be the best one so far.
DroidFish 1.49 with Critter 1.6a engine is the STRONGEST Android chess App today. The second option here is Stockfish 2.3.1 engine.
We are all waiting Houdini 3 Android, but nothing seems to happen since January. When will it be released?, Robert has the last word. He wants to be sure the program will not be cracked . I think it will be released before summer, but who knows.
Houdini 3 will be the other choice, as Hiarcs Android will not be available till Christmas, being optimistic.
On a second level we have Shredder and finally ChessGenius.
Other interest options are Mobialia, Dark Knight, Chess Game and AMobile Chess, the last three older DroidFish versions.
Either ChessBase Online or playchess.com will incorporate an analysing engine in future versions, may be during this year.
I will update my articles here when Houdini Android be released , as there are already interesting novelties, above all chess courses and learning tools.
The FOUR best Android free chess apps just now are:
- DroidFish 1.53 DD, including Stockfish DD engine by default.
- Go to Richard Vida´s web, author of Critter program, and download last Android UCI engine version, 1.6a, and charge it on the DroidFish 1.53 platform. Read carefully the instructions for doing that.
- Do the same with the new Senpai 1.0 ,UCI engine version.
So you will have three fantastic engines into the DroidFish platform.
- But the New Boy On The Block ,that just arrived , is called Professional Chess Free ( Chess Pro Free). Terrific, for me the BEST Android chess app just now, better than the former three above.
And all of them are FREE.
Enjoy them, together with Shredder, ChessGenius and Mobilalia, and FORGET the rest. !!!
Mr. Dudido111, PLEASE don´t tell ME about DroidFish. I am DroiFish BETATESTER and Spanish translator, so you can NOT tell me anything new about that app.
I am testing it just now with my new smartphone Wiko Highway Octa Core, using EIGHT cores ( 2 GHz each) and 2 GB of RAM. I also got it on my Samsung Galaxy Note 3 phablet and Galaxy Note 8.0 tablet, and in my also new one ,the Galaxy Note Pro 12.2 P900.
I got the best UCI programs on them, including the Critter and other FORTY ( 40) more engines, obviously at another level. I included also the BEST opening books either Polyglot (Morphius, RpC...) or Ctg ( HIARCS, PowerBooks...). And obviously the complete Gaviota TBs ( 6.54 GB).
BUT in this moment there is a New Kid On The Block. Just a few weeks ago arrived the Professional Chess Free app on Google Play. It is a Stockfish version with optimized use of massive memory, and for me is the NUMBER ONE chess program in Android today. After nearly 200 games and many position tests, it goes deeper than Stockfish DD, gets a much better balanced and realistic evaluation function, and maintains and avercomes the terrific playing level and style of SF and Critter.
So "by far" has no sense today, and PCF for me, seeing the results, not only comes close but beats DroidfFish best engines , Stockfish DD and Critter 1.6a.
By the way, I am ALSO betatester of both, and I am now testing their new versions..., so I REALLY KNOW what I am speaking about.
Hello, I recently developed a free android application. It's not dedicated to chess, but could be a pretty good tool for chess study. This is basicaly a web browser, but it has pgn support... With it you can :
- open/read/search pgn files.
- create little notes with your own chosen chess pgn games included, and write about those.
- display chess games from your phone on your tv, phone, pc, tablets (with chromecast, or anything that has a web browser).
- backup up, wikipedia chess related pages as web archives for offline use (if you intentend to study chess in the hymallaya)....
Some screenshots (the chess related one, is not at the beginning) :
I prefer chessbase for poopdroid
I'm actually more interested in android apps that emphasize learning and study.
I feel that computer engines are already so strong that unless you're 2500, you're nitpicking when it comes to selecting the 'strongest' one, since all of them will be so good that they'll outperform your analysis every time.
I'm still lacking a good openings and endgames trainer.
For tactics, I've been very happy with Asim Pereira's ichess app - you can import your own pgns into it! His Analyse This is also excellent.
The ChessOCR app is shockingly good as well - it really works! Very handy for the inevitable book figures where you wonder "why can't I play h5?" but it's not addressed in the text. Takes two seconds to both scan it and send it to another app for analysis.
I recommend My Chess Puzzles app if you like to solve chess problems: