Android: INSTALL_FAILED_UPDATE_INCOMPATIBLE

I keep running into this issue about once a month.  I build and deploy my app to my Android device, and at the end of deployment I get the ambiguous error:

INSTALL_FAILED_UPDATE_INCOMPATIBLE

This thread in the Xamarin forums gives a variety of different solutions, but I wanted to document it for myself and others in a nice clear list of things to try, in the order of easy-to-do first:

1. Uninstall whatever version of your app is on the device and try to deploy again.
2. Install the app store version of your app, uninstall it, and try to deploy again.
3. In the system Settings/Device/Applications/App Manager on the All tab, find the
   

   com.<appname>.<anypackage>

   Select it, uninstall it, and then try to deploy again.

This third one is sure-fire way, so you might start with that and skip the trial and error.