We use Jira from Attlasian. You can assign work hour estimates per task.
Developers can burndown the hours for a task, an you can see which task took longer as planned.
So this is a: "Jack worked 4 hours in Issue TEST-13, TEST-13 now has 5 hours remaing estimate"
kind of report.
There is also the "activies" view, wich is more like a blog roll of everything that happened in the project.
So more of a. "Jack stopped working on TEST-13. Jack closed TEST-12 with a comment 'works for me'" mind of report.
In our Team, we don't use the hour estimates, but whenever I was away for a day I allways look at the "activities"to see what has been going on. This is no replacement for talking to the team of course, but it helps me framing some questions.