Android users may be late to the Threes! party, but it's still a party. A party with math 'n' stuff.
Sirvo's acclaimed iOS puzzle game is now playable on Android devices (4.0 and up) in exchange for a reasonable $1.99. Combine numbered tiles to form threes, then sixes, and so on and so forth. It's an immediately graspable concept, one that fosters fierce competition. Play it!