This app was mentioned in 1 comment, with an average of 8.00 upvotes
Interestingly, the city and the U of O came up with an app for bikers to identify potholes and other bicycle hazards so the city can address them. It uses the GPS and camera functionality to report issues. It always stumped me why it wasn't widened to the whole host of things that you can report on the city's, uh, (I forget the name...Public Works?) website. It could easily be used to report illegal camping as well.
I mean, all the pieces are already there.