WIP scraping library for Polish e-register mobiDziennik made in Go
Check out examples/ folder for individual examples, however if you want to see reference implementation, check out my abomination of a desktop app - mobiNG (hehe funny name).
For developing MobiAPI you'll first of all need access to mobiDziennik, a web browser and a basic understanding of Go and probably how various web technologies work and a proxy for intercepting network trafic. I can recommend ZAP since it's what I've been using but it's cross-platform and open source but you can use anything. MobiAPI type already has a function for connecting to a proxy server you can use.