Of course, you can vary the percentages to you liking but this has worked great for me so far...
Where I went wrong was being too eager to get the business and getting started on a project without getting any money upfront.
If they are serious about the project and generally a professional entity ( person/business ) they will pay upfront..otherwise run like hell.
You will obviously make a few mistakes along the way but you will get the idea of filtering clients the more you consult.
Some clients can be more demanding than the others, but in general as long as they are paying, you will be alright!
Good luck and thanks for the great post!
Did you do anything special for Debt Snowball that made it more successful than your other apps, or was it just a good product?
Do you do all the design and code for your apps, or do you outsource graphic design?
Are you worried that developing on 5 platforms will spread yourself too thin?
I do all the code and I've done varying levels of outsourcing the design. I've done all the design for some smaller apps, I've hired people using elance.com, and more recently I've been partnering with some top level designers (Debt Snowball+ was partnering with a really good designer).
As for spreading too thin, I hope not. I won't be doing all of my apps as I don't have nearly enough time for that. There is only 1 app at this point that makes sense on desktop, and I only plan on doing the most successful apps on the other platforms for the time being. We'll see how it goes, but I think the diversification will be very much worth some amount of spreading thin.