Cast Your Vote - Cast Your Vote is an app that allows you to set polls and a voting system and know the answer to your question.
Stack Overflow - Community-based Q&A part of the Stack Exchange platform.
My Vote - My vote is an app that allows you to create ranking, ratings, polling contests, and view the results either after voting closes or in real-time.
The Answer Bank - The Answer Bank is the UK’s leading question-and-answer site.
Pollie - Create polls and share them via your favourite tools
Askalot - Askalot is a next generation CQA (Community Question and Answer) system.