Android App resets after printing

[antroyd]

I attempted to get a BT01 printer; unfortunately, vendors do not use the printer ids as as listed in the documentation for this. The device I got identifies as SC03h-1135-1135. The app prints on it when the "Test Unknown Device" option.

My device runs on LineageOS22.1 (Android 15).

1. The app did restart with the set-up screen (language, theme). Currently not reproducible, now it start right to the printing page. Previously made settings were maintained.
   Once the app is set-up, setting should be maintained.

2. The app does forget unknown device; for every print job, I have to rescan for devices.
   Once a device has been found compatible, it should be kept as default printer until a scan for other devices is triggered.

3. Could the device SC03 (?) be included to the list of compatible printers? (Could contribute any data which might help you with this integration?)

4. An option for changing the language should be added; it eases issue reporting.

Finally: Please keep this app alive; it is a lovely FOSS tool.

[hpsaturn]

I have a similar problem with a device with ID: SC03h-D4CD, but I already reached give support to it to this Arduino library in this PR and it is working there:
bitbank2/Thermal_Printer#73
I don't know if this could help to this kind of printers that they are compatible with the iPrint app on Android (closed source)

Also I found this repo that have some information around this iPrint protocol and these printers:
https://github.com/lisp3r/bluetooth-thermal-printer

This printers works like other cat printer using this Arduino Library, but they have some differences in the quality when you uses the original iPrint app. For this reason could be nice support these with this nice open source alternative.