Is there a successor to CSipSimple?

The goal is to use the CSipSimple on a TMO Galaxy S5 . I found the .apk files, however they are dated 2012: https://code.google.com/archive/p/csipsimple/downloads CSipSimple-0.04-01.apk installed but returns an error at boot up: > Can't load native library CPU arch invalid for this build 1. Is there a simple fix to overcome the error message? 2. Is there a successor (fork?) to CSipSimple? 3. Is there a version of CSipSimple that is Marshmallow compatible? Ideally there would a site that stores more recent .apk files.