We have an existing Windows Mobile application, including source code in a combination of Visual Basic and C#, communicating with a SOAP-based web service.
The application is for field service workers. The main screen of the application displays to the field worker a list of work requests. On selecting a request, the worker can a) view more details on that request, b) view details about the customer, or c) enter a new time sheet against the request, which can optionally be signed on-screen by the customer.
Our desire is to have this application ported to a modern platform so it can be used on readily available commodity smart phones and tablets.
We are flexible on the target platform, but all else being equal, we will choose a portable solution over one tied to any particular vendor's products. i.e. we're likely to prefer HTML5 over an Android or iOS-specific implementation.
Note that the existing SOAP/XML-based web service can not be modified because it integrates with other systems.
At a stretch, we could possibly be convinced to accept a gateway service to convert the SOAP/XML to REST/JSON, but you would then need to provide this in the form of a Microsoft IIS-based solution.
The existing source code includes a web service proxy for the client end, written in C#.
The signature is captured using a proprietary algorithm that captures the signature strokes into a specific compact data structure. The source code for this is also in C# and will need to be ported, as the captured signatures are viewed in other systems which cannot be changed at this time.
Screen shots and/or limited source code (e.g. XSD schemas for the data) can be provided to prospective bidders who would like more information to help them estimate the work required.