InSaver is a messaging and contacts app for Android, published by Video Downloader Story Saver.
Features of InSaver
Contacts sync from the device address book, so setup is mostly a matter of granting permissions.
Build details
This build is version 3.26.0 Build 30887, the download runs to about 42MB, and it needs Android 7.0 and up.
The change in this release is listed as Premium Unlocked. Check the file against the scan result on this page before you install it.
Installing
Allow installs from unknown sources for whichever browser or file manager you used, open the downloaded file, and confirm the prompt. If an older copy is present and its signature differs, uninstall that first.