This project appears abandoned. Unless word is heard from the developer after this post I don’t think you should consider purchasing this software as it is incomplete and highly buggy to have such an egregious price of $30.
This looked very promising and I would really like to see development continue. Hopefully this gets some form of response so we know what the state of the project is. I understand life happens, but radio silence is not the way to handle it.
The developer does have a web app that appears to have some similar functionality to this paid app some people may find useful. There are no links on their site to it and I had to crawl to find it.