How to break Mobile Software

In the last days I tested a few apps from colleagues of mine. I found some nice bugs which I often found by doing similar actions, It didn't matter if this was an Android, iPone or Symbian app.
Somem years ago I saw a presentation of James A. Whittaker at a conference in Munich, this guy had so much fun in breaking software. He actually wrote some books about testing:
"How to Break Software" and "Hot to beak Security"

In the last days I had probably the same fun trying to break those mobile apps. Some tipps from the book can be applied also on mobile apps, some other things where different, so maybe it's time for:
"How to break Mobile Software"

Here are some things that worked for me:

(Mis)Use Copy and Paste
Most smartphone supports copy and paste nowadays. And with this nice feature you can start attacking all kinds of ui elements. Assume there is an input field with some limitation, this could be the lenght of characters allowed or characters that are forbidden to type. Try to paste illegal stuff into it. This often works and is a well known test-strategy on desktop applications. It's time for bringing it to mobile phones!

(Mis)use Multitouch
Since iPhone Multitouch is the next big thing for user interaction. But it's even better for an evil tester. Try hitting 2 elements at the same time, whether it 2 listeelements or 2 icons. Most applications are not designed to be protected against this. There is no deselect between the events so the app gets out of sync. Often a thread is started for an action and there is no synchronization that could stop this. Chances are high that you create strange effects on the app. And if the app get's into a strange situation for example overlapping menus: don't stop! This is your chance, now you have good chances to crash it and win by knock out.

(Mis)use Softkeyboard
Since the iPhone started a huge amount of devices came without any keyboard. They have so called soft keyboards that appears where needed on the screen. Try to get the keyboard at a point where it is not needed and use it. Maybe you can confuse the app.

(Mis)use Orientation changes
Accelerometers are more than a nice toy. But writing orientation aware apps isn't easy. Ever saw text falling out of it's boundary dialog? Try to rotate the device in the middle of an action, maybe you have the luck to find such a problem.