At the moment, direct backup import is supported for Nova Launcher backups.
To migrate from Nova:
Create your backup in Nova Launcher.
Open the backup screen in Smart Launcher.
Select restore/import and choose the Nova backup file.
Smart Launcher can import that file from the same screen used for Smart Launcher backups, so the flow is the same.
After import, quickly check widgets and app shortcuts, then save a new Smart Launcher backup once everything looks right.
If you are coming from another launcher, you can still migrate smoothly by recreating the home layout manually and then saving it as a Smart Launcher backup.
