When I had to call Russia I remember using telbo and hotvoip, when you load the account the funds never expire and hotvoip had sip settings so you can use it as one of your dial out accounts on your smart phone. Then when you dial out you can choose which dialing account you want to use. If you look at my call history you can see that I dialed out some using public mobile and some using Hotvoip. Now it's hit and miss on data connection but it always goes through when your WiFi is strong, so totally depends on the quality of data/WiFi. The call quality is pretty acceptable for the price. I believe it was about 1-2 cents per minute. Telbo had 90 days free than it would use the balance, but I think it's long gone after sanctions.
