I saw a preview over on G+ for Green Lanterns that mentioned a dating app for superheroes. And I started thinking about an app for supervillains and superheroes. Not to date, but to have combats.
Actually, I'm not joking (though I'm sure it has been used as a joke).
Here's the thing: if you have a superhero world where there is a significant amount of celebrity to being a super, where the business of threatening the world and saving the world are objects of interest. Seanan Maquire's Velveteen stories are the kind of world involved.
Now, there probably isn't a market for such an app...but there would be a market for the generic hookup app you imagined first...and it could be a feature in the app. A dating app essentially lets you present a profile to people and it allows people to filter out candidates and choose from them. Really, the same app could be repurposed for a number of things. The pool of possible candidates is probably small.
You a hero looking for another hero to date or hook up with? Use the app. You can filter based on sexual preference. Heck, you can probably predefine whether you want someone who self-identifies as a hero, as a villain, or something else.
And if you were a person with a fixation on dating supers (or a particular super) wouldn't you really want the app so you could maybe meet your dream? Superheroes have to have groupies. Heck, supervillains probably have groupies, which might make for an interesting evening...trying to find the young man who wanted to date Ivory Toxin, the supervillain who sweats mind-altering chemicals before he succeeds and finds her).
And, just to bring us around to the idea of things you can use in your supers games, wouldn't that be exactly the kind of app you'd want to hack, so that the phone involved would always be telling you where a particular super is at any given time?