Looking up the APIs for android would defiantly help. client server would be the easiest to set up. Or, something that i am doing in a game i am making, is to have a web server and your application hit the web server for updates and whatnot.
This is working really well with a turned based game I am making. Might take more capital up front, ie. Hosting your own web server, but since android supports SQLlite, you are good to go. :)
