There are examples on github from the beforetimes (preai). I made my own little version with a basic ui in python a couple years ago. Works pretty good. Best to pull the powertab or guitar pro tab versions though and open in tuxguitar.
Here is what I was cribbing from with my own version. Seems they updated it since.
Let me introduce you to freetar!
It currently has issues due to cloudflare blocking, however I have already created a pull request that fixes this [0].
Given the code is pretty straightforward, turning it into a scraper shouldn't be too hard of a task!
as far as i remember only the Pro tabs are paywalled (the ones created professionally)? the community tabs are all freely available on web, and carry little restrictions on mobile
Exactly why I can get behind a scrape here. They are already freely accessable.
I don't like having to switch to desktop mode to transpose though. They want you to get the app to do it on mobile which is enough of a reason to make a special program to do exactly what I want.
Also, scraping chord charts is in a different catagory from tabs. I can't even actually read tabs but with a chord chart you can get close enough to noodle around and emulate. Good enough for my needs.
Here is what I was cribbing from with my own version. Seems they updated it since.
https://github.com/jabbey1/UGDownloader