What are some alternatives?
When comparing Doorbell.io and UseResponse, you can also consider the following products
UserSnap - Usersnap Track is your central place to organize user feedback and collect bug reports. One screenshot is all it takes. Get rid of endless email exchanges and coffee-stained sticky notes. Your new life is awaiting you!
Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
UserVoice - UserVoice integrates easy-to-use feedback, helpdesk, and knowledge base management tools in one platform that empowers users to speak and companies to understand.
Invision - Prototyping and collaboration for design teams
ZenDesk - Zendesk is a beautiful, lightweight help-desk solution.
UserEcho - Online customer support solution - Feedback Forum, Helpdesk (ticketing service), Knowledge Base and Live Chat by UserEcho