Rated 5 out of 5 stars
I loved the simplicity until I started experimenting with adding a category. Most people would not put tags within categories and so this would not be an issue. Also, if you do manage to set up tags within categories, using them is easy.
I would rate as 4.5 if I could, but I gave it 5 stars because the features are good and the utility is excellent.
Instructions for those who want to set up tags within separate category folders:
1. Click the drop-down on the toolbar and click Edit. This brings up a Preferences window.
2. Make sure you are on the "Edit Categories" tab.
3. Click the "New" button.
4. Replace "New Category" with the name you want for your category/folder.
5. Do not try to move any tags you see on the right side of the window to the left. It does not work (or at least did not for me). We need to add tags a different way.
6. Click the "OK" button.
7. Right-click on the toolbar and pick Show-> Category.
8. Click your new category, then click "New tag..."
9. Name your tag. Optional: Click the button to the right of the tag name to assign a color.
10. Click OK.
11. Right-click on the toolbar and pick Show-> Text.
You have now succeeded in adding a new tag to a new category. Use the drop-down button on the left side of the toolbar to switch between showing all tags and just the tag(s) of your category(/ies).
By the way, note that "Recent Tags" shows the most recently used tags regardless of category.