same here not really sure what i have to do tbh
The app scan your headset to see if you have some apk files to install. If you don't have apk files to install, it's shows nothing ;-)
It avoids you to browse your directory (for example download folder) to search the apk you want to install. The app lists itself the apk files it found. For example, download QGO and then start this app, it should show you the QGO apk then you just have to click to install