Backstory: Last Friday I wanted to go to happy hour but it was 6:00pm (most happy hours end at 7:00pm). I spent a few minutes on yelp finding the closet bars, reading their menus and trying to find a decent happy hour. It was nearing 6:15 and it would be almost 6:30 by the time I got to the nearest bar. I spent wayyy too long trying to find a decent happy hour.
The Idea: A location based app that give you the time left until happy hour ends (minus drive time).
Deep Dive: The app could function similar to yelp but feature a countdown timer for each bar's happy hour, letting you know how much "happy hour" time you have left. The app could branch into ratings/reviews, giving you the "best" happy hour with the most time left.
Validation: I've seen a few happy hour apps come and go. Making this one location and time based would help solve both problems that I haven't seen incorporated in one app.
Monetization: If coded correctly, you would make money off this. It may not be worth your time initially but it's more of a fun hobby. This would be a longer play with building a community of resellers and either selling very few licenses or building something else and promoting it to your new community.