@vkc
The "app" concept requires bundling business logic with a front-end, and to think about ergonomics, and this can be a blocker for having contributions from certain kinds of people that aren't big front-end fans, and would contribute desktop free software in the form of libraries or CLI programs.
#geeqie, the desktop linux image viewer, is rather wonderful for niche use cases because it allows in particular:
- to view images it doesn't know about by use of identification / preview plugins by calling CLIs;
- to do arbitrary things to images by having plug-in contextual menu actions, also calling other programs.
And this mechanism allows for arbitrary "simple" business logic code processing images, for example this "receipt to monochrome PDF" use case.
I do have many such personal "plug-ins" for geeqie and others, and I was thinking that if some people are technical enough to have des-crooglized their phone, they could be technical enough to rely on a generic "power viewer" file-manager-type app that would allow them to process their data with similar plugins, but because business logic deployment on Android is not exactly easy, the app could favor for example using REST APIs on personal web services... or having an intent "protocol" for requesting work from small apps that don't have sophisticated front-ends.
Personally, I'm just not doing much on a phone, and instead for receipts, when they aren't scanned by ADF, connecting my phone to a proper computer, pulling the last picture by adb, and processing it on the computer...