I got the app; took awhile to download but finally came up.
One of it's requirements is that you first sign out from Gmail (and Google Voice I think) before it will run. I missed doing this on one of my computers which held me up.
The folks who built it seem very responsive with answers and new versions.
Making unlimited wifi calls back to US while international could make this the best $4 I ever spent.
Here is an ongoing thread at one of the Android forums (he said an iPhone version will be coming)
forum.androidcentral.com/optimus-v/79598-new-voip-option-gv-single-app-solution-groove-ip.html