The MobiLink plug-in for SQL Central was redesigned in version 12. In previous versions, the plug-in had two modes: Model mode and Admin mode. The MobiLink functionality was split between these two modes, so you needed to be aware of which mode you were in at any given time.
CustDB is a sales-status application. The CustDB sample is a valuable resource for the MobiLink developer. It provides you with examples of how to implement many of the techniques you need to develop MobiLink applications.