Is there a way to see app feedback I've sent on Android?
It looks like you can't send Google Feedback reports to specific apps (although, as Dan Hulme commented, Google does forward them to the developers of the app on which you are reporting) - as you said, it's a system-wide option. You can visit https://www.google.com/tools/feedback/reports?hl=en to view feedback reports that you have submitted while logged into a certain Google account. However, I have not been able to find anything on viewing crash reports themselves that you or your device have sent, automatically or otherwise.