I have now tried Progress Bars of Life, and surprisingly, it has a different purpose than Barbecue -- not suited to my need.
PBoL is focused on tracking time progress: set the time or date target, and it counts down for you. But it is cumbersome for tracking irregular progress in concrete units such as pages or chapters read (what PBoL calls "manually set range"). To add units requires 7-8 clicks:
- Progress Bar Items (if not already focused)
- Name (double click)
- Current Value
I don't want to go through all that every time I add a unit or two of progress. Obviously PBoL is optimized for automatic time progress, not manual addition of progress.
Furthermore, the bar color -- green to yellow to orange as the time limit approaches, then red as the limit is passed -- is more suited to a time countdown than, say, tracking the number of games played.
Barbecue is focused on tracking non-chronological units rather than time. For this it is slightly easier than PBoL because only 5-6 clicks are required:
- Tray icon (two clicks, depending on configuration)
- Title (if not already focused)
- Show meter bars
- Close or Escape
This could be improved, as I suggest in my comment below.