I am not going to be putting up a public bug tracking system, but you can report bugs here. There will be in app reporting (via email perhaps?) soon, but for now please use this form or send an email to email@example.com.
When reporting problems, please include the type of device you are using and the version of Android it is running.
Please provide as much information as possible about the problem and what you were doing when you encountered it. It is always better to provide too much, instead of not enough, information.
If possible, please also include the data you have entered. If you would like to submit a screen shot, please attach it to this report.