Gruveo is built on WebRTC, a technology that enables browsers with real time communication capabilities. As any new tech, WebRTC is developing very rapidly and is sometimes rough around the edges.
We have recently been alerted about an issue with Gruveo users on 64-bit iOS devices (iPhone 5S and above, as well as newer iPad and iPod touch models) having difficulties connecting to Gruveo running in recent versions of Firefox.
The underlying cause for the issue turned out to be a bug with the particular build of the WebRTC library that the Gruveo app was using. We have promptly switched to a different, working build of WebRTC and submitted an update to the App Store, which just got approved.
Grab the latest version of Gruveo for iOS from the App Store and let us know how it works for you!