You'll be happy to know I actually have two planned features along these lines!
- I'm going to add the ability to exclude tags by alt clicking on them (or something along those lines), which will show everything that doesn't have a given tag
- I want to implement the following filters:
- "Show All Untagged" which shows all items that have zero tags
- "Show Not Manually Tagged" which is the same as above, except it includes items that only have auto-tags
As for other suggestions, at the moment, since the app is so small, it's pretty informal. I might come up with a system in the future, but for now, you're free to just jam whatever suggestion in here.
Thanks for trying the app out :)