This is stock CM10 Mms with sliding conversation UI (Hangouts style). I made this because I like the interface of Hangouts but don't like the SMS integration. So, I prefer to have a dedicated SMS app and this is what came about.
Sliding conversation UI (hangouts style)
Pop-up reply (CM)
Quick reply from notification (CM)
Mark read from notification (CM)
Display who most recent message in conversation list is from
Breathing notification icon (enable in settings)
Contact picture widget regular, small, or gone
This is a work in progress so feel free to report any issues. That said, I've been working on this for a while and everything should run smoothly
Download from play store here (easier for me to detect/fix crashes, but slower updates) or attachment below.
Copy to device and install normally.
adb install SlidingMms.apk