If you have a phone lying around, you can turn it into a Nextcloud NAS. For turning my tablet into a monitor, spacedesk is the application of choice that I used here. It only takes about five ...

According to this link, adb reverse was introduced in Android 5.0 onwards, so, to use this feature, your android tablet can not be 'that old'. Data is unencrypted! (Relevant for public network ...