I have a Galaxy Grand Prime phone that's about a year old and the Google Play Store lists it as not compatible with this version??? Any idea why or if I might be able to use this app anytime soon?
This functionality was a big selling point in my decision to buy a Code 50 and it doesn't seem to work.
I control many other Bluetooth devices with this phone, so it's not a limitation of the phone.
I had the same problem last week when I bought a new phone. The solution for me was to download the gateway apk file from http://apk-downloaders.com/marshall-gateway/ or if that doesn't work https://apkpure.com/marshall-gateway/air.com.marshall.gateway
Move the file to your phone, and install. Be sure to allow android installing from "unknowns sources" in settings.