Unfortunately, there is not a print service app in Windows CE developed by Zebra or a third party partner available.
We have several sample code examples that you can follow to implement your own solution.
You can review this article in the Zebra Knowledge portal that uses the Zebra Windows CE SDK:
You can download the Link-OS Zebra SDK on the link below:
There are some sample code examples that are part of the EMDK which can be downloaded from the support site.
The EMDK for .NET has these two examples: CS_PrintSample1 and CS_PrintSample2
You can download them from the link below:
The EMDK for C has the following examples: BasicPrint, Win32PrintSamp
You can download them from the link below.
Another option that you could try is by using Rho-mobile. There is a Motorola Adaptive Printer Driver (ADP) developed that may fit your needs.
For more info, please, go to the link below.
I realize you may have already finished development. I wanted to post that there is now a Zebra compatible printer service for Windows CE/Mobile devices that we have available through the RhoMobile suite. Rhomobile | Printing
I don't know much about the direct API's to the service, but you can use the RhoMobile Suite or (I believe) Enterprise Browser for development with it.