In about 30% of cases when I move into my wifi coverage area, Zoiper fails to register properly. It remains in "Registration Failed" state until I open Settings>Connectivity and reclose it. It displays "Restarting Zoiper Service" then registers successfully.
Perhaps the problem occurs because signal strength varies back and forth until Zoiper gives up trying to register? Then a different algorithm would perhaps help. The phone can't just give up for good. Perhaps wait 30 seconds then try again?
As it is, the app is unreliable when moving around with Wifi on. Manual turning wifi off and on is just not an option for me.
Great app otherwise!