I am working on a project which is basically a Notification System or in other words sort of Lan Instant Messenger for mid-size companies, in which a person can update the status of the project (like twitter) and the others working on the same project will be notified, they can also add their comments. I am implementing it in C# & it'll be windows based application. I have been asked to include some more features in the application, so if you got any advice or suggestion in order to extend my application please do mention...
You're giving a very vague overview on an idea you're working on without an actionable and answerable question about starting a company. Can you be more clear about a specific question you have about your startup?
From what I gather - You should setup a UserVoice account and let your customers vote on features. This is the easiest way to get feedback on your idea from the people who will actually buy it.
Im not going to write a full prd for you, but here are some features that would be nice to have:
A feature I would like to see is the ability to set up this application without any centralized server apart from a file server. This would ease the setup enormously in many companies.