What language/SDKs one has to use in order to write windows 7 apps? Is the overall experience different from iOS/Android app developing? How do one test the apps?
Visual Studio Express is a free version Microsoft makes available so it isn't like you have to buy Visual Studio. Here's a good tutorial on writing a quick Windows Phone 7 app using VS Express: http://weblogs.asp.net/scottgu/archive/2010/03/18/building-a...
What is the difference between free and paid version of VS? My internet speed/prices doesnt allow me to watch videos online, or download such big software as VS, but I will soon go back to uni in Singapore, so I am starting to think what should I do there in order to earn some cash...
The free version doesn't allow add-ons to be installed in the IDE. I think that's about it. The free version does allow you to make commercial apps, contrary to some postings I've seen about it.
The Express versions are not designed for multilanguage projects. For example, in the paid versions of VS, you can add C# and C++ projects to the same solution. You cannot add a C++ project to a Visual C# Express solution.