Richard has a few ideas for apps, but doesn't know how to build and program one. Leo says that Ideas are really a dime a dozen, and the key is how he would implement it. Apps are programs and if he wants to learn programming, that's where he could start. There are specifics for learning not only how to program, but also iOS and Android, and the API (Application Programmers Interface) for each platform. To learn how to program, there are great MIT and Stanford programming courses online for free on iTunes U. Then, there's Coursera.org, and Big Nerd Ranch.
He can always hire a programmer to do it for him, too. Check out eLance.com.