This is a great app, but it can use a brief user guide. At first I thought it was too rigid.
Then I found two things that helped:
1) you can edit the start and stop times after they have been recorded.
2) You can tap the timer to stop recording time.
Now it is very useful because you can see your history for the past few days, and how much time you spent doing something.
BeachBiker about BusyBox - Track your time