Ah, texting apps...
I LOVED Chomp SMS - I loved the customization. Then it began to glitch; so I tried a few others and ended up with Textra. I really liked it, and upgraded to the Pro version. Their support staff was excellent - you could message them with a glitch and they would have it resolved/have a response sent to you in a matter of hours/a day or two. Really good tech support, so I wanted to support them. Not as heavy on the customization front as Chomp; but they were still quite good n that regard.
Now that I have my LG G3, I'm trying to stick with the stock messaging app that came with the device - I like the theme customization for each contact; and the font can be changed (overall on the phone, but still) and the speech bubbles, so I'm pretty happy with it. I'm also trying to minimize the amount of apps on my phone - trying to keep things simple. However, if I had to choose an app, it would be Textra Pro.