Go to the ApopheniaBTC website, https://apopheniabtc.com/, then click on the distorted picture.  Input the information required (your BTC receiving address, your guess) then click "Bet".  You'll then be given an address to send the displayed amount of BTC to.  After a confirmation or two, if your guess was correct, you'll receive your BTC!

I've played a few times, and even got a few answers correct.  It's a great game that doesn't take up too much of your time and it can slowly drive you insane when you're sure you know what it is... then it cleans up the photo a bit more and you were way off.