Are you sure it’s legit? From a quick look at the official GitHub repo’s README, I saw no mention of a native Android app (however I did see mention of the iOS app).

EDIT: dug a little deeper and saw mention of the Android app in the latest release notes (beta coming soon to the play store) as well as an empty Android studio project folder in the source. Maybe the actual code is somewhere on a different branch, but even so, I would be hesitant to install random APKs not coming from the developer themself.