Can I call people who don't have Viber?
Yes, if the person you're calling doesn't have Viber, the call will be placed like *regular call, but don't forget to invite your friends to Viber so your next call is free
*Regular calls are calls placed through your cell phone service provider, using your cell phone rate plan.
So if you have no cell, the call "should" go through Google Voice/GrooveIP, right? But that can't do anything for call quality (other than reduce it). I see no point in trying it on a wifi tablet.
Originally Posted by ViberMedia
Viber does not officially support Tablets, but it should still work with most of them.
If you have a WiFi only Tablet, then the call simply cannot be routed through your cell provider (because you don't have a SIM card). So you shouldn't worry
Download it and try it out.