Version 1.2 of Chess for Android at the Android Market has several improvements. The first is the much requested "undo" feature, where up to eight plies (half-moves) can be taken back to correct mistakes in the input (or mere blunders, as for black in the screenshot below!).
The second is a "free play" option, where the phone can be used as a "magnetic chessboard" to study games, or play a game up to a position for further play with the chess engine (this option, like the different levels of play, can be found under the "Menu" button). Furthermore, move highlighting has been modified with a black border, which looks slightly better along files and ranks. Finally, a few rules were added to evaluation function of the chess engine.