I bought LEAP in order to see if such a software is able to fit with the mess in my brain. Also, I have never read any document about "how to use" correctly this software.
For my brain, a good software should be able to be used intuitively. In that way, LEAP is not so bad.
But I found a complementary software to add tags more easily (Tags.app), by selecting 1 or several docs (email, pdf, image, ...) and pressing CTRL+Space for exemple, a Tag window appear and you can add your tags. They are recognized by LEAP also. That is really very convenient.
I use also Papers to organised my PDF files (list of publications). Papers is nice for bibliography (for scientists) as it generates a folder in which the PDF are classified by year, journals, authors, ... That is great and cheap.
But today, I made a big mistake combining Papers and LEAP, and I want to share this bad experience. I wanted to add tags on some PDF files in the Papers window. It did not work because the folder was not identified by LEAP. I could not really understand what does it mean.
LEAP : On the right side of your screen, you can find 3 options (tag, ?, file) to bring a doc/folder in LEAP. I was thinking that by draging the pdf folder into this window ("file", LEAP would be able to recognize the folder containing the pdf files that I want to tag from the Papers window.
I don't recommend you to drag the Papers folder in the "file" (managed ?) : I found all the PDF files renamed in LEAP and of course no more associated PDF on Papers. CTRL-Z was not working to repair this bad operation !
Then I decided to select the files from LEAP, and to drag it in Papers ! At that time, all the classification was lost, and even I could read all the PDF, the author and journal list was lost. Then I had to identify one by one each pdf and the associated authors/journal/year ... (about 2000 pdf files) !
So please never try this operation, or read "how to use LEAP" before trying any operation with important documents !
Hope this comment will be helpful !