Mobile devices are considered to be very useful in adhoc and team collaborations, for example in disaster responses, where dedicated infrastructures are not available. Such collaborations normally require flexible and interoperable services while running on mobile devices and being integrated with various other services. Therefore, middleware and toolkits for developing mobile services which can be accessed by using standard interfaces and protocols are in demand. Due to the lack of tools, the support of the development of Web services and collaboration tools on mobile devices is still limited. This paper presents the Vimoware toolkit which allows both developers and users to develop Web services for mobile devices, to conduct ad-hoc team collaborations by executing pre-defined or on-situ flows of tasks, and to test collaboration scenarios.