I definitely don't want to be orwellian about it. That's why it's not about sharing your location, it uses your location to work out where you are, but it only shares who you are with, not where. If you want to find out where someone is, you'll have to message them using a seperate app.
Foursquare checkins support tagging who you're with, as do facebook posts, it's definitely a "single-feature" app that is already done by the bigger companies, but I think the ambient location aspect (detecting when you're with someone) and the focus on just 'Withs' might make it a viable app.
It's also a bit different from foursquare, since it's easier to share when you're 'With' someone at a private venue, which might happen more often to teenagers who aren't so often at a foursquare venue (bar, cafe, etc).
I answered below, but basically post your location every 15 minutes to a server, and if you and a friend are near each other, send a notification asking you to 'check-in" with this person.
That sounds like it would take an awful lot of battery though. And it would mean most of your friends would have to have the app for it to be "useful" don't it?
I've been running the prototype on my phone, and doesn't seem to use a noticeable amount of power at the moment. But you're right, all your friends have to be running the app for the detection to work.
It detects by sending your location to our server every 15 minutes. If you and a friend both send the same location, we send you a notification asking you to check in with your friends.
As to making money, I don't know - maybe using one of the existing in-app ad networks, with a $1/year upgrade to pro version with no ads?
Ignore the crazy motherfuckers in this thread, jesus. Like I said on reddit, use phonegap, angular and maybe a simple ruby on rails backend if you need something on the server. That'll be the easiest way to build the app, and you'll develop great marketable skills.
Everyone is gonna give you advise on finishing and tenacity.
Have you thought of the opposite viewpoint - that it seemed like a promising idea, but once you fleshed it out you found out there's reasons why no one else is doing it?
I'd say you're doing it exactly right, keep working on projects, find out if they're dead ends or not, then move onto the next one.
If you want to improve your process, make sure you focus on prototyping and UI, and not worry about stuff like scaling.
Also - opensource your half-done projects on github, so you can have them as resume pieces.
Foursquare checkins support tagging who you're with, as do facebook posts, it's definitely a "single-feature" app that is already done by the bigger companies, but I think the ambient location aspect (detecting when you're with someone) and the focus on just 'Withs' might make it a viable app.
It's also a bit different from foursquare, since it's easier to share when you're 'With' someone at a private venue, which might happen more often to teenagers who aren't so often at a foursquare venue (bar, cafe, etc).