An online bug tracking system with minimal functionality?

Question

Bug tracking systems

There is a program, the code is closed . But you need to organize something like feedback with users so that they can report bugs or suggest features. In short, you need

1. Creating messages by users
   
2. What would it be a site (and not a script that needs to be installed on your host)
   
3. Non-flashy design
   
4. free
   

Answer 1

Bagzilla. Not ? Kind of like a de facto bug tracker.

Answer 2

There is also trac.edgewall.org
I would advise you Intercom or UserVoice, but both of them are paid.