Zendesk - Zendesk is a beautiful, lightweight help-desk solution.

productboard - Beautiful and powerful product management.

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

ProdPad - ProdPad helps your team gather ideas, surface the best ones and turn them into product specs, and then put it all on a product roadmap.

HelpScout - Help Scout is a simple, straightforward way to provide excellent support

ProductPlan - Cloud-based product roadmap software solution