R – Windows service for windows mobile

Just create the app as a Console app. If you need a message pump, you need to call Run without any parameters, and the CF doesn't have that. OpenNETCF's Application2 class in the SDF does. At that point you can raise a UI any time by creating and showing a Form as usual.

You cannot create a true service for CE or WinMo with managed code because EE Hosting is not supported.

To get your app to start, first we need to define "On".

There is "On soft reset": Here there are a couple choices. By far the easiest is to just put a shrtcut in the \Windows\Startup folder.

There is "On resume from sleep." This is a bit more complicated because you have to run something before that happens. The simplest mechanism here is to register your app with CeRunAppAtEvent with the NOTIFICATION_EVENT_WAKEUP event. You'll have to P/Invoke it, as there is no built-in managed method for it.

Edit: There is also "After hard reset". Some OEMs provide a mechanism to run an app or do some form of logic from a cold boot (Symbol for example). You'll have to check with the device OEM's docs for how this would work.