Zevra is a weak engine written by Oleg Smirnov, around 1700 in Rapidroid scale. The Android build still causes issues on my devices, like the previous 1.4 version: A remarkable % of the games played with black by Zevra needs to be replayed after a division. I keep hoping Alexei can find the trick behind this problem with Chess for Android.
However, you can always try Zevra with Droidfish or for human vs machine games in CfA.
In case of trouble downloading from PC, use your mobile or refer to THIS POST.