Startup Idea : Real life dating app (location based)

Let´s create a very simple mobile phone app that you activate if your single (or not but are on the lookout anyway). Just a few parameters: gender, what gender you are interested in and a selfie (mandatory, no more than 30 days old). The parameter set and your location will be transmitted to a database and everyone else with the app will be able to browse through a catalog of users with close location (200 yards). Add a blocking and invitation filter where while browsing you can go invisible to anyone you don´t fancy and can give a green light to anyone you´d like to meet. Stop it there (no chat or messaging functions) and let real life take it from there. Does improve the batting average though as you´d not try to chat up anyone not interested or in a relation. Should be easy to program and set up but would need a critical mass to get started. but that could be overcome by locaized promotion... Imagine: seeing someone nice/interesting somewhere (train, caffee, bar, campus) and getting a green light... no more wondering about missed opportunities. No more real life disapointments from online dating