SMS

If there is a native app already installed I tend to use that such as is the case for texting and email. The native app does everything I need and since I can change themes with TouchWiz now, I can also change the look of the SMS client.
 
Do third party apps like Textra and Google Messenger support RCS Advanced Text Messaging? I'm on Tmobile.
 
I have always used the stock messaging app on my Android phones up until a couple months ago when I discovered Handcent. I am all about customizing the look of my messaging app and Handcent is the best one I've found so far. You can set pictures from your phone as backgrounds on the conversation level and UI level. It also has cloud back up, delayed sending, scheduled sending and much more. Really liking it.