My idea is to creat a social networking app for smaller, specific events. There are big social networking sites that allow you to check in at certain places (like a concert for instance) and you might happen to see that someone else has also checked in at that concert, but it's not very interactive. This app would create an area where everyone who is in attendance can upload images, make comments, share information, and interact with the other people attending the same event.
When you open the app, you will either be creating an event or you will be attending an event. If you are creating an event you will choose from a list of possible events to create. One example would be a wedding. You would set up the title, maybe add information about the couple, how they met, the engagement, the wedding party, an itenerary of the events taking place that day, and polls or fun quizes that guests can participate in. You could also set up a list of suggested 'tags' specific to that event to help guide guests when they are uploading images or making comments . (i.e. #cake, #firstdance, #ceremony, etc.) You would also set whether this event is public or private. A wedding would probably be a private event and all guests would need to enter some sort of passcode to enter the event. A public event (such as a concert, art show, sporting event, charity event, etc) would show up in a list of events occuring in my area.
If you are attending an event, there would be a sign with a QR code that would link you directly to the specific event you are attending by prompting you to download the app. (this QR code would be generated by the app when the user is creating an event) The GPS on your phone would also be able to detect if you are in the general area of any events taking place and give you a list to choose from when the app is opened.
This app would allow people to share pictures and memories from a single shared event in order to add to the overall experience and gather all collective assets and media in one area for everyone to enjoy.