I think you could consider this app a twofer. Not only is it a game to challenge others and yourself, but you can also get faster at texting people in your day to day life.
Become the typing king with Thumb Master for BlackBerry 10!
Challenge yourself and your friends as you pit yourself against others to become the
fastest Thumb Master ever!
Current version includes Quick Mode – make that quick fox jump and fast!
– Fun animations as you type
– BBM Integration – show your friends you are the Thumb Master!
– XTreme Mode!
– Daily challenges
– World-wide leaderboard
Get it for 99 cents at Blackberry App World.