The current version of the app doesn't work properly on android 8.0 Oreo or higher since it doesn't have permission to install apps from unknown sources.
It's a new permission that was added at android 8.0.
To fix this problem, you have to add the following tag to the manifest:
<uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
I've downloaded the source code and added this tag and managed to run correctly this app on an android tv 8.0 emulator using android studio.
I hope you upload a new release for this app with this fix, It would be wonderful!