*updates on the bottom
I've played for over a year with Clash of Clans: a very nice mobile games.
Day by day, the game become more and more difficult to play without spending money.
It's the classical in-app purchase free game mechanism: pay to survive.
During the game you have a limited shield, that can save your village from attacks for others player for a max of 16 hours.
Of course you can extends the shield with money.
When you have no shield, the others people can't attack you if you are online and connected.
My first attempt was to put the display of the phone in a "never sleep" mode and leave the app open but this was not a working solution, clash of clans see that you aren't do nothing and it disconnects.
Later I was thinking about an hardware solution with arduino, that could simulate at least the swipes on the touch screen, something like this hack for another game: https://www.youtube.com/watch?v=SnUH6f_Mv8o but there was an easier solution.
UiTesting with UiAutomator
One of the android's tools is called uiautomator http://developer.android.com/tools/testing/testing_ui.html it is used to test UI on apps, so it is possible to write test/programs that simulate click, swipe and other actions on apps running on the phone.
What I have done, it has been write a simple uiautomator test that:
1 - it presses home
2 - it searches clash of clans in the list of apps
3 - it launches clash of clans
4 - it waits 15 seconds for the app to start
5 - it does swipes movement
6 - it waits some seconds
7 - it repeats from 5
I tested the app on my phone (no root required) and my village was opened for
Update #1: 18 Aug 2014
Yesterday I posted on reddit this post, to understand the reaction of some players and what they are thinking about it.
On reddit I've discovered that after 6 hours of game, Clash Of Clans automatically disconnect the client for 5-10 minutes... but, my hack (I'm lucky) keep on try to reconnect during this period and at the end of this period it is correctly reconnected.
I have also discovered there are some hacks out there that works with rooted phone and works in similar way.