Want to test your mental acuity, or want to be challenged by the best brain teaser ever! Download Tap20 for free! This is much more like a free test than just a game, it teases and taunts you with its simple yet interactive gameplay. Tap the jumbled number from 1-20 in the right sequence to score your best. Tap20 is an addictive creation of cactac studios and is free of ads and in-app purchases. The finger tapping game is available on iTunes and Google Play Store both.