We just released an update to Mobialia Chess including themes for the board and pieces. You can check all the available themes at http://www.mobialia.com/chess-themes/ and install them from Settings->Theme.
Also, if you are a design freak you can also build easily your themes. A theme is a zip file (but with the extension changed to .chesstheme) that can contain one or more of this files:
- playing_background.png: 1024×512 background image for the 2D board
- piece_set.png: usually a 450×150 image with the PNBRQK images for the 2D board in two rows (whites up)
- light_square.png: square image (usually 64×64) with the texture for the light squares (for both 2D and 3D)
- dark_square.png: idem for the dark squares
- light_piece.png: square image (usually 64×64) with the texture for the light pieces in 3D
- dark_piece.png: idem for the dark pieces
- board_border.png: square image (usually 512×512) to be used as the table for the board in 3D
The chess app will open all the files with the .chesstheme extension: to install a custom theme, you can open it from any android filemanager and the “Open with” dialog will pop-up including the “Open with Mobialia Chess” option.
Also, if you create a theme please send it to us and we will add it to the official page.