Generally I like it and it works. Here are a few notes:
1) When a prompt comes up "click to focus" is written across the screen. What does that mean?
2) Although it appears that my cursor is in the box where I need to type, typing does nothing. I must click my cursor on that same spot and then type.
3) Entering tone numbers is fine. However, the display shows a tiny gray tone number (too small to really see) and the tone mark - redundant.
4) Once I finish typing and see the result, the click anywhere to advance does not work, I must click on "next" to advance.
As others have commented, putting down the pen to type at the keyboard is cumbersome. While it is not consistent with SRS and the mixing of various types of practice is effective I wonder about pinyin-only practice. Sometimes doing something a little different is a welcome change, and it would sidestep the keyboard transition issue.
Good work!