N-hance.io - Task prioritization tool, inspired by the 7 HABITS book, the #1 Most Influential Business Book of the 20th Century.
Priorities - A todo app for today and tomorrow only
PrioIt - Prioritize tasks and items using comparative comparison
Know Priorities - Product prioritization made better
WittyCat - Synchronize and prioritize your team's tasks day after day
1st things 1st - Strategic prioritizer that helps you make up your mind.