vcgencmd missing on OrangePi2+

No chance. vcgencmd is a special tool for RPi’s firmware as a part of VideoCore Tools.

http://www.elinux.org/RPI_vcgencmd_usage

With a android app, no. But you can use a Browser on mobile phone and Linux Dash or PhpSysInfo or RPi Monitor or NetData

I personal prefer RPi Monitor for all my devices (NanoPi, OrangePi, Odroid, CubiTruck,…)