I've been trying to get user feedback for some time for https://pingr.io and it looked like a hard thing to accomplish, since people usually don't want to check your product thoroughly.
To my surprise there is a place where I got a lot of feedback and suggestions for free.
Moreover, I got feedback from technical point of view (guy event pointed out some staff directly related to my stack I used, like "hey you got a console error because of...").
Here is the place:
The important thing is: