A free app for Android, by Chess King.

This is the first of three volumes of a course by Chess Informant. It contains over 250 exercises for beginners and intermediate players. Each exercise consists of two parts. The first part is a puzzle, while the second part is a game. The puzzles are meant to be solved by using only the information provided. If you get stuck, the program will help you out by giving you hints and explanations. The game is played with two players. You play against the computer, while the other player plays against you. The goal is to win the game by getting more points than the other player.

This course includes a free part, in which you can test the program.