Simple Poll - The easiest way to create polls in Slack
Pushbullet - Pushbullet - Your devices working better together
GitHub Polls - Polls for GitHub issues and readme
Pushover - Real-time notifications on your Android, iPhone, iPad, and Desktop
Curious Polls - Answer a question once a day for the chance to win £100/$100
Gotify - a simple self-hosted server for sending and receiving messages