InviteRobot - Instant subscription for paid Slack communities
Roomvine - Chatrooms for real life venues, neighborhoods and events
SlackPass - Subscription access to anything with Slack
Spectrum - Browser-based app to visualize the frequencies of an audio file.
Grapevine Surveys - Grapevine is an online survey tool for employee surveys.
CityBugs - Improving cities to make them a better place to live in.