Others have covered the legalities, but I'd wonder - as a useful question to ask in general - if it's as good an idea as you think.<p>A lot of the value of any idea comes the execution - which doesn't mean the code, it means the marketing, branding, support, networking, customer acquisition, and reputation-building.<p>Unless it's a very unusual idea that needs minimal customer interaction - they exist, but are rare - or something that works solo (games, mostly) you should budget time and money for all of these.<p>Many apps are killed by the support process, not the development process. The app sells, bugs appear, customers get various shades of irritated and angry, negative reviews are left, and dealing with all of this can turn into a huge time sink if you're not planning for it. This is even more true of projects that have a significant server back end.<p>The app store is full of abandonware left by devs who didn't realise how much extra work is involved in turning an idea into a reliable income stream.<p>I'm not saying it can't be done, but I am saying it needs some consideration before you go ahead and spend time (weeks? months?) on a clean-room rebuild of everything you've done so far.