Bar Rollcall Version 1.0
https://bar-rollcall.herokuapp.com/
Using Yelp's API, you can search for bars in your area. You then see information about the bar and the number of people who have used this app to check in to that bar.
You can then check in to these bars, after logging in using Twitter's API.
A cron job runs every morning to set all the attendance numbers to zero.
This was made to fulfill an assignment for FreeCodeCamp, described here: http://www.freecodecamp.com/challenges/build-a-nightlife-coordination-app