I don't get it?? Release notes say this version is updated to for "SDK 27," otherwise known as Android 8.1, however after trying this newest/current version, it failed to work on my much older device running Android 7.1.1.
Installed all the versions from 2.0.6., up to this one, 4.0.6. The earliest version that said it supports Android N, was 3.0.0., so gave it the benefit of doubt and installed the version released right before the one I needed, bcuz well I already DL'd and Installed, like 7 different releases, what's another one?? 
Simple Easy Answer = ~ 2 mins of my life wasted that I'll NEVER get back!!
Multiply that by, the 7 other versions I tried and.... Well, you get my drift.

This app won't work at all on a ZTE Z982, on 7.1.1., don't make the same mistake I did. Use the 15 mins or so I'm saving you, spending it with loved ones instead.