The caveats: There is a $199 startup fee, which gives you a LG Optimus phone running Android 2.3. Phone choices is a bit limited and I wish they allowed you to BYOP - Bring Your Own Phone. They call this "Hybrid Calling" because their service uses Wi-Fi networks by default for voice and falls back to Sprint's cell network if no Wi-Fi networks are available. If use too much actual cellular data and the company and they'll ask you to get back on track, but will eventually give you the boot.
If you're in range of Wi-Fi networks on most occasions, this certainly makes for an inexpensive cell phone plan. They claim most people are in range of Wi-Fi networks 60% of the time. This definitely has some niche applications. I can see parents giving this inexpensive offering to teenagers for instance, though this service should simply prevent further cell calling if limits are exceeded instead of booting the customer. Let 911 calls through obviously even if they've exceeded their limits.
Of course, if Google offered WiFi calling via their Google Voice platform leveraging an Android app, then Google could kill republic wireless. Though Google would tick off their carrier partners in the process.
Check out Techcrunch's take.
