Considering the Geo-coordinates of the rooms of you house are configured in the app, when you move from one room to other the message (say a welcome message)on the screen should change.
Say moving from Drawing room to kitchen , Message should change from "Welcome to Drawing room" to "Welcome to kitchen".

At top level there are 2 approachs to solve the problem

1. Use location of the handset.
2. Use place a bluetooth device in each of the room, the app on the mobile shows message based on the device in range.

MyGeoApp uses first approach i.e use the Geocoordinates to solve the problem.

 Using Geofence is an obvious choise for this usecase, but the limitation with GeoFence is that it supports only Circular region. So we use Ray-Casting Algorith to check if the point is with in a polygon.

• MainActivity.java is the entry point of the application.
• It uses android native Location service to handle the locationChange events.
• Each room represents a polygon, coordinates of each room is pre-configured/hard coded as of now in the app.
• On locationChange event the Ray-Casting algorithm is executed on each room(polygon) and message is displayed accordingly.