It shall be very simple. A map like google maps where you can add a location for example of an homeless person you saw. If you know him a bit better you can for example add information like his favorite food or something. Everyone who is around this city and has this app can see that and help him or make someone a nice day with his favorite food, a coffee or clothes. I would suggest different categories, that you can search for example for homeless only. So you can also help in other ways, like someone who needs somebody to drive him to the doctor or whatever. With this app you mighty end up helping your neighbor in the garden if he needs help...

Someone new in your area needs help? There could be a notification for all which are close to him.

For Christians this app shall not replace the fellowship of Jesus. The holy spirit shall remain leading you, but it shall awake your attention for people in need and make others to helper as well.