Thank you for your reply!
Yes, ive read that link.
I think GPS wont be enough to locate the user inside the school, as our school has 3 floors, which makes it pretty hard for the signals to come trough correctly.
Right, only military grade gps-like chipsets and devices, sometimes using classified satellites, can accomplish that and it doesn't work if the building is lead shielded although I don't think your school would be. Forget about it for a typical Android device.
Do you have any "tutorial" on how to write code for locating the user with other techniques ? Like, triangulation for example ?
Not really, but you seem on the right track. Choose the technique (algorithm) e.g. triangulation etc.. you are going to use before looking for code.
Im starting on my application now and I wonder how I should mark the map with the coordinates ? I guess this is my problem now lol
The sky is the limit, you could have a 0,0,0 point in the middle of the school second floor or find out your school accurate elevation and longitude/latitude and map based on that. I would probably choose the latter.
The main challenge that I see is that I assume you won't have control over the Android devices. It would be much easier if you provided the devices to the users. You are basically left with triangulation based on the different Wi-Fi access points in your school given their signal strength. I don't even know if the Android devices would be able to handle that.
Another option would be a facial recognition-like program where the user would point his Android device camera to a barcode-like sign on the wall to let the application know where the user is. Edit: using that, you wouldn't even need and accurate positioning system. You would only need a high-level knowledge of the school layout, more like a human mind would do.
Let us know what you come up with please,