Backup & Restore exports your entire Simple UI configuration to a single portable .sui file. Use it to protect your setup before a firmware re-flash or plugin update, or to copy your exact layout, bars, and style to a friend’s device (or your other e-reader).
To access these settings, open Simple UI’s Settings (tap the Settings button) and go to About → Backup & Restore.
A backup is organised into selectable categories, so you can share just part of your setup if you want to:
A small set of core settings (such as whether Simple UI is enabled) is always included regardless of which categories you pick, so a restored backup boots into the same shape it was exported from. Internal bookkeeping (migration flags, caches, debug data) never leaves the device.
.sui file is written to koreader/settings/simpleui/backups/ on your device.