Looking for "best" older android phone that Groove IP works "flawlessly" on (or at least good voice quality with few problems). I use it on my Nexus 7 and have no phone. I use T-mobile Wifi Hotspot for 4G. Just want a phone to leave in my car (or pocket), just for wifi calling (when I don't want to use my N7). Cheaper the better, but will pay for quality.