I have been working from home for seven years now writing software and selling it to other companies. I'm really having a lot of success on the Mac App Store, bringing in a respectable salary from that alone. If you're curious about my apps just type "Rebrand Software" into the Mac App Store.
The trick is:
-Make your apps available in every language supported by the app store
-Rating is more important than price. Make your apps low price until they have 4/5 star ratings, then you can raise them slightly.
Doing this I'm selling 50-100 apps per day at $2 to $3 each. I use RealStudio (http://www.realsoftware.com) to program for Win/Mac/Linux, it's easy to learn and there are tutorials for getting your stuff on the Mac App Store. When the Windows Store launches with Windows 8 I'll be in a position to immediately put all my software on it.