smartChord does make backups automatically on the external storage.
In the ‘Backup’ feature, you can create a backup anytime. There you can also restore any backup. The backups are stored in the backup folder of your device storage. You can reach the ‘Backup’ feature by the menu on the ‘Home’ screen.
From there you can copy a backup file to the backup folder of another device and restore in the ‘Backup’ feature.
You can use the ‘Share’ functionality in the ‘Backup’ feature to send a backup to a save place or to another device where you can restore it.
smartChord also detects backups after an new installation and asks if it should be restored.
The backup folder is something like /storage/emulated/0/Android/data/de.smartchord.droid/files/backup where ‘0’ can differ on your device.