This is the Mint Theme add-on to the chompSMS application. Once installed, access the theme in chompSMS > Settings > Theme It! Note: requires at least chompSMS version 6. 34.
Chomp SMS Themes is the official developer of the app which can be found in the Personalization category. Over 10K users downloaded and installed Mint Theme and the most recent release was on Aug 31, 2015. This application has the overall rating 4.3 on Google Play.
You are able to download the .apk installation package of Mint Theme 1.4 for free and take a look at users' reviews on Droid Informer. This file size doesn't exceed 441 KB and the app runs flawlessly on Android 2.2 and above. According to the antivirus report, the app doesn't contain viruses or any kind of malware.