I am planning to develop a simple application to help freelancers. What would be better to start, web or desktop application?
That's it? No more information? Basically a toss up. Choose the one implementation that will be the most helpful to freelancers. Since we don't know what it is, I can't help you any better than this.
Since you don't give much info, but specified it's something simple, probably web would be the option. It's easier to make people use something online than having them to install your app on their computers.
when in doubt do both. Make a web app and desktop application then give your target the option on what they would like.
I have to say, that you have to give your clear idea even though it is not perfect, and even you want to ask us brainstorm. We do not order you any thing so If you want to have ideas, analyzing,... from us you must give us more. It is not matter if it is desktop or web apps.
Web: you have to make sure your code works in the main browsers Desktop: you have to make sure your code can be installed and work in all the main OS Personally, having done the desktop program and suffered through the support issues, I'd go for web. You have a lot more control.