Brothers as partners

I am writing for advice before my sons get started on a partnership. My oldest son came up with an idea for a phone app. My younger son is a computer guy and will be doing all of the work to develop the app and also has come up with his own important significant ideas to enhance the app. My oldest son will do the paper work such as setting up the partnership accounts and will research and acquire legal protection etc.. I will do the payroll and tax work for free for them My question is what should the percentage of profit be between the two boys. I don't want the boys in the future if this idea works to be at odds with each other..

Keeping the peace before they start.

Thanks for the help

via Small-Business-Forum.net http://www.small-business-forum.net/starting-your-business/10535-brothers-partners.html