OKRStudio - Connect Trello cards to OKRs. Manage OKRs inside of Trello
productboard - Beautiful and powerful product management.
OKRs.app - Reach your personal goals with OKRs
Aha - Aha! is the new way to create visual product roadmaps. Web-based product management tools and roadmapping software for agile product managers.
Perdoo - OKR methodology, software and coaching
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.