Simple Poll - The easiest way to create polls in Slack
Curious Polls - Answer a question once a day for the chance to win £100/$100
Twitter Polls - Polls embedded in tweets
Polls for WhatsApp - Create & share quick polls in your WhatsApp groups
Live Reacting - LiveReacting is a platform to launch interactive streams on Facebook, Youtube and Twitch.
GitHub Polls - Polls for GitHub issues and readme