I'm seeing a lot of apps that assume too much. They assume I've got GPS. And even if I had GPS they assume it is turned on. Same for Wifi or any data connection. Therefore a lot of crashes occur because of null pointer exceptions.
The simple fix is ofcourse to null check or to use a little more of try and catch.
Specifically, most apps should be able to perform their functions off-line. Why? Because mobile data is expensive and unpredictable in a lot of countries. You can't expect that 3G will be on and working, and you can't expect that someone will be inside wifi.
FWIW, anecdata and all that, the majority of people I know in NZ prepay for data in chunks that roll over multiple months, and so they only turn on 3G when absolutely necessary.