I use TextFree (think they're trying to rebrand as Pinger). You'll have to text from a phone number OTHER than your cell number, but once you've explained to everyone why you text from a funny number you don't call from, it's pretty seamless. I've gone so far as to have AT&T block all text communication cos I don't believe in paying an arm and a leg for something that should be free in this age.
Sent from my HTC PH39100 using Android Central Forums
I have used TextPlus. Great and horrible at the same time. Layout looked too much like iOS. Unlimited phone calls in, unlimited texting, ads. The horrible part is when it gets uninstalled. It leaves a file on your microSD/microSDHC card that you can't delete and you have to format the card just to get it off. "Sit emptor cavete".