About this app
Welcome to Zone 21 - Fast Math Solitaire a brand new card game where you can win real-world rewards and cash prizes (where available)! Try to stay between 0 and 21. It's not easy and tries to keep the target number close to 21 to earn more points! It's a jackpot when you get exactly 21 and earn great bonus points. SOME KEY FEATURES: • Classic mathematical card game with some amazing twists! • Clear the cards from the table and stay between 0 and 21. • Ready for the challenge? Try to hit the target number 21 and get great bonuses. MULTIPLAYER FEATURES: • Play against friends and solitaire around the world! • Calculate cards as quickly as you can! You have 3 minutes to beat your opponent. • Win and show off your scores on the leaderboard! EARN PRIZES: • Challenge people from around the world • Put your skills to the test and compete to win cash prizes! • Cash rewards for top scorers (where allowed)! Challenge people around the world with Skillz, a competition platform complete with leaderboards, trophies, physical or virtual prizes, and an amazing loyalty program that rewards you for playing! If you have any questions or proposals for the game, we hope you contact us at support@ccbrothers.com If you have any questions about the Skillz system or cash tournaments please contact: support@skillz.com
Latest release
What’s New
• bug fixes
Audience growth
Ratings growth
Baseline captured. Growth appears after the crawler observes a changed rating count.
Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.
Price tracking
Price intelligence
First snapshot captured. The trend line starts after the next crawler price observation.
- First observed Aug 15, 2026 · 6:13 AM Free