TravelFone (san.easyroam) on Google Play
This program will automatically switch to VoIP mode when you are in roaming and have Wi-Fi access. Simultaneously, program will automatically redirect all incoming calls to our Ukraine-based telephone gateway. When Wi-Fi signal is lost, everything is reverted.This is useful when you're roaming, and your call-forwarding charges to Ukraine are smaller than incoming roaming call charges.This is absolutely useful if you're Ukrainian resident.