An easier way to reach the app in Android is the Google Play store. It's named Austin 311 from City of Austin. Some negative reviews, though, like (20 Jan 2023) "You can't report when your trash doesn't get picked up - easily 99% of the reason I ever call 311" and (9 June 2022) "App sucks. The categories are very limited and hard to locate. I should be able to search on a keyword and your app suggests appropriate categories. Where do i report a malfunctioning pedestrian cross signal, for example. Very disappointing!"
I just checked out the Web page. That has a search capability (I don't see one in the app), both built in via a Search text box, and the browser's own facility (except there are not many items per page). I think I prefer it, even on my phone.
But the Android app at least has a map of recent reports, which is a nice feature; I don't see it in the web page. It also has one central place to enter the reporter's info; it looks like the Web page has it on each request.