Issues Tracker for both developers and end users [closed]

Question

currently, we have a closed source project on hand. However, we would like to have a communication channel together with our end users.

• We would like to have our end users to know, what features we are currently working on, and what features they are going to get in next release.
• We would like to know users' thought, on our planned features. They may always provide input/suggestion on our planned features.
• We do not planned to host on our own server. Hence, a ready-available service is welcomed.
• But we would like to remain our source code in closed model

Is there any web based service available for this purpose? Free or commercial doesn't matter.