Well, I think this is only a nice bar, but after a day or two I was using even more and more.
I think this is a special feature and helps very much with specific buttons.
It’s an open source project using private APIs, which would break the App Store rules. If it was malicious it wouldn’t survive long on GitHub. The original author also has several apps on the store.
There are actually many great apps that haven’t been put on the App Store, eg. Handbrake, Forklift FTP (latest version). The App Store is great, but it can hinder the features of some apps.