applications - App isn't working correctly. How can I fix it?

I have an application that isn't working correctly. Either it's not launching, or not responding to commands, or some of the functionality isn't doing what I expect.

What are some simple steps I can do to try to fix the issue on my own?

(This question and answer are intended to be a canonical and generic source for dealing with apps that aren't working quite right.)

Answer

The steps to take with an app that just isn't working properly are:

• Rotate the device

if that doesn't help

From Settings | Applications | Manage applications | or Settings | Apps | (depends on your version of Android)

• Force stop

if that doesn't help

• Clear cache

if that doesn't help

• Restart the device (turn off/turn on the device, or use the "restart" option if you have it)

if that doesn't help

• Clear data

and if that still doesn't help, try the nuclear option:

• uninstall and re-install