Alternative to Google's "Messages" app (for SMS) on Android? - SDF Chatter

Does anyone know of an open-source alternative to Google’s “Messages” app [https://play.google.com/store/apps/details?id=com.google.android.apps.messaging], which takes care of SMS/text messages on my phone? I was looking for open-source alternatives on PlayStore and F-Droid [https://f-droid.org/] but can’t really find anything – most apps seem to target some extra purpose than simply handling SMSs. Cheers!