Calendify - Calendify is an event community where you can share, publish, and subscribe to event calendars. It helps you to stay informed about what you are interested in and what is yet to come.
ilo - Premium Twitter analytics
Vamos - Local Event Discovery
Tweetastic - Better Twitter analytics, scheduling and more
Morse - Create, shout out, and discover nearby events in real time
Accountanalysis - A tool to evaluate Twitter accounts