The best way to improve your Chess is to look at instructive games and Chess Prof presents the best games for each level with useful commentary.
The focus is on a Principle based learning which will develop the thought process. The Principles are highlighted in the practice games which bring out important concepts to focus on.
Chess Prof also allows you to submit your own games for expert analysis to help you learn from your own
The app provides a robust mechanism for capturing games including main line and variations, comments, and outcome in a user friendly manner.