Recommendation for simple project/task time tracking app
In the end, I found Timecop that does almost everything I wanted: simple project tracking with a variety of configurable reports spanning days, weeks, or months.



Honourable mentions go to Tictoc which does a very similar job to Timecop, and Timing (which also has a free, Lite version). Timing is different in that its a "traditional" application tracker, however, you can create custom projects and drag applications into them, right down to the document level. So you can attribute different documents in a single app to different projects, which is great if you're working on two different projects in Xcode, for example.