We have similar lists, so some considerations:
- Helium314 fork of OpenBoard for keyboard
- Simple Gallery for your gallery (just purchased but there is an emerging fork I'm blanking on the name of)
- Matrix with a Signal bridge so you can use tablets and other devices with Element, which has a wider range of devices
- NeoLauncher is like OL, but with more configuration
- Thunder for Lemmy. Great client, and only one with 2 column tablet support