In my personal experience that application has never run properly for me or given decent quality on my ov. I've not been able to hear the other person or them not hear me and there is always latency even on WiFi network
If anyone is having trouble using GrooVe IP I'd be happy to help. Just send us an email at snrb.labs.com. We've continued making improvements to the app and the latest versions should have significantly less latency than the older ones.