Track Other Devices With Gps, Android?

I am working on an application which will be installed on around 50 devices. I will be getting the location of all those 50 users in every 5 minutes. I have a small concept tell me

Solution 1:

In my opinion you must need a webserver and via using the web-services you store all the latitude and longitude onto the web-server with the unique device id. Once you got the latitude and longitude of all the devices then by using web-services just sync the data and show their location on the map. For the movement you can draw a route by refresh the web-services in every particular period of time.

Solution 2:

You need have some backend which will keep all device location. On each device you need to have service with timer to push current location every 5 minutes and pull location of others users. I don't see any other solution for it.

For displaying you just need Google Maps. I recommend to check this: http://www.vogella.com/articles/AndroidGoogleMaps/article.html

And after just keep ArrayList with your marks and refresh their location on map every 5 minutes.