Nick of Time
Obtaining this secret achievement will be hard and tricky 
You need to win a game with less than 1 second left of your time (0.7 seconds for example).
Might help to play lots of lower time format games, like bullet and blitz, one day you will get it.
My advice is to play hyperbullet (30 seconds games) and make sure you have premoves enabled. It's the fastest way to get this achievement.
You can also risk and take a chance at it: when it's your move and you have mate in one, pick up your piece and just hover it above the mating square. Watch the timer and if you are fast enough you can place the piece and deliver the checkmate in that time frame of less than 1 second. Good luck with this!
