You can see graphs over your total caffeine intake throughout the day, the last week or last month. The caffeine tracker also predicts your caffeine levels 10 hrs ahead based on your current level.
New drinks are added to the caffeine tracker all the time and new features will be added with each version.
Note that the levels suggested by the tracker app are not fitted each individual user, and should be taken lightly. Feel free to to write feature requests to help improve the tracker - they will be considered.