Kaivan,
Our product that is designed to support MRS thoroughly is called "Service Manager". Service Manager is for SAP CRM while Work Manager is for SAP ERP. We can give you a reference tied to Service Manager and you can see if it helps you out.
http://service.sap.com/sap/support/notes/2014454
There are a lot of request on how to improve Work Manager to interface with CRM (even though it is for ERP). The Customer Service addon is the closest one for the feature to support customer but the main backbone is still ERP. So there may be better improvement for Work Manager Customer Service to get more features in the future but ultimately Service Manager is the main product for CRM.
Regards,
SAP Mobile Support Team