Each player has 21 tiles: 12 tiles with 5 squares, 5 tiles with 4 squares, 2 tiles with 3 squares, 1 tile with 2 squares and 1 tile with 1 square.
Players take turns in placing one tile onto the 20x20 board. The first tile for each player has to be placed in their corner of the board. Each following tile has to touch a corner of one of your previous tiles, but it must never share an edge. It may share edges with the opponents' tiles though.
If a player has no more possible move, they have to pass. The game is over when no player can place a tile.
For each player, the squares of all their tiles on the board are added up. Finishing a game with all stones placed on the board gives a 15 points bonus. If the monomino is placed last, you will get a 20 points bonus. The player with the most points wins.
HOW TO PLAY:
•  Swipe the list of available tiles with your finger.
•  Select and drag a tile onto the board.
•  Rotate the stone using one of the 4 handles.
•  To flip a stone, slide your finger from one handle toward the opposing handle.
•  Place the tile in the desired position. The tile will appear green if the position is valid, and red otherwise. Possible corners are highlighted on the board for convenience.
•  Tap the tile in a valid position to place it.
•  You can rotate the board at any time to see the opponents' tiles.
Quit the app at any time, your current game will be saved and restored on next start.
•  Supports 2-player modes, with 2 colors (Original and Blokus Duo), 4 colors (2 each).
•  Customizable board sizes other than 20x20.
•  Play against the computer or humans on the same device.
•  Play online against your friends
•  Hint and undo options
•  Leaderboards and Achievements (Google+ login required)
•  Looks great on tablets, too!
The game is network-compatible with Freebloks 3D for Windows and Linux: http://www.saschahlusiak.de/freebloks-3d/
Freebloks 3D is absolutely free, open source and without advertisement! ALWAYS! But things for free can still have a value. If yoy like to pay for Freebloks, please consider buying Freebloks VIP:
The complete source code is available on GitHub: https://github.com/shlusiak/Freebloks-Android
If you have any idea, feature request or wish, simply drop me an email: firstname.lastname@example.org
TRANSLATIONS: if you would like to contribute and translate Freebloks into your language, please send me an email. :-)
Author: Sascha Hlusiak
Market link: de.saschahlusiak.freebloks
Web site: http://www.saschahlusiak.de
Market downloads: >250,000
Market rating: 4.3 / 5.0