Hi,
I went through your description and have a clear idea that you want a developer who can develop snipping tool that allows a user to take all or part of a screenshot and save that image, edit them with multiple functionality like draw with pen, using highlighter, add text,etc also you want us to develop something which can be uploaded onto the server directly form the app itself, in short you want me develop the develop an application with similar functionality which are provided by Microsoft in there windows system and upgrade it to a modular one.
See, the problem which arise while making these applications are many, we have to create an application which get noticed there is immense and crowded competition of mobile application similar to the one in the market so developing an application which get noticed is a plus point.
The other problem is the application should be self explanatory i.e. we have to work on a application which is simple, productive and presentable user interface, so we have to build an application which is great with UI/UX.
So while developing an application we have to keep it our mind that "what to do" and "what not to do".
I will feel great helping you with it and discussing more onto the following application before implement your idea into a real time application.
Thanks And Regards,
Sunil Sharma