I guess I'm a lazy guy. I'm just using OfficeTime on my iPad, iPhone, and Mac. Works well for me. A menubar app to help me with starting and stopping the timer to keep track of time spent on a project. It syncs with my iPad and iPhone. I can also keep track of time spent on those devices as well. It also has an export routine to make reports in a spreadsheet or word processor.
One of these days, I might try to check out Workflow's API and if-this-then-that to see how it works.