If the stock SMS app on your phone isn’t powerful enough, EvolveSMS might be just what you need. This app has a ton of features, including Marshmallow fingerprint authentication. You can set a time-out in the settings, after which you’ll have to touch the sensor to unlock the app. All Marshmallow apps support the automatic backup system. In the case of EvolveSMS, it’s an essential feature as it will automatically restore your conversations to a new phone.
EvolveSMS (free plus $1.49-2.49 in-app)