I built a free opening trainer with spaced repetition : feedback from Chess.com players wanted

Hey,

I kept blanking on openings past move 6 in real games. Not because I hadn't studied them, I had. The problem was passive study (videos, databases) builds recognition but not recall. You know the line exists but can't produce it under pressure.

So I built Knightline. The idea: treat each board position like an Anki flashcard, reviewed with SM-2 spaced repetition. Instead of replaying a full line from the start every time, the algorithm tracks each position independently and only shows you the ones you're about to forget.

How it works:
- Learn mode — every move has a coach explanation (not just the move, but why)
- Drill mode — play the line from memory, get corrected when wrong
- Quiz mode — position appears, you find the right move
- Smart Reviews — SM-2 schedules what to review and when

It also connects to your Chess.com account: pull your last 100 games, detect what openings you already play, and build a personalized repertoire based on your actual game history. So if you've been playing the London for months it won't tell you to switch.

436 lines across 29 families. Free tier is genuinely usable. Web app, nothing to install, works as a PWA on mobile.

knightline[.]app

Specifically curious about Chess.com players' experience, does the game import work well for you? Any openings you'd want added?

Good idea! 😉 These filters are actually already in the app. You can tweak the time controls, rated/unrated, and date ranges right now. Let me know if it works the way you expected!

Thanks a lot! 🙌 Let me know if you have any feedback or ideas to improve it after playing around with it.

Well I'm HOOKED and I've only been on for 30 seconds. One issue - on Chrome dark UI, the grey tiny text is difficult to read (attached). Maybe try size/color shift?

I'm VERY excited to see how you flesh this out over this next year!!! We have so many great tools for chess and it's quite exciting. Thank you!!

ADDED: BTW, I agree the unselected items can be grey. A User would only look once to know what those items represent and wouldn't care unless it was highlighted. But the labels and the text to the left of the red button etc ... it is so difficult that I simply don't see I'd be able to use your app. Maybe it'll be more clear on my iPad - I'll check.

Wow, thank you so much for the kind words! 🙌

You are 100% right about the contrast on the dark UI. Good catch. That grey text is definitely too muted, making it an accessibility issue. I’m going to tweak the color/font-weight to make those labels and the text next to the button much more legible (without losing the dark mode vibe).

I'll push an update for this very soon. Let me know how it looks on your iPad in the meantime, and thanks again for the detailed feedback -> this is exactly what helps me improve the app!

It crashed MacOS Tahoe Safari when trying to create an account. 2nd time didn't crash, just waiting for the email now... I'm looking forward to this!

Haha no worries at all! They show up in the personalized repertoire flow after you enter your username -> easy to miss on first pass. You can filter also in your profile your Lichess / Chess.com openings. Let me know if the filters work the way you expected once you find them!

Just pushed a fix : should work smoothly now. Thanks for reporting that and let me know if you run into anything else!