Having a great idea for an iPhone app and making it a reality are two very different things. If you're a programmer, then you've got part of the battle won, but not all. And if you're not a programmer but you have this great idea that just won't quit, you can plan on spending a lot on the development, all before you even know if the app will be profitable.

The first step in the creation of an iPhone app is, of course, the idea. And not just an idea, but a good idea--a great idea. This is important, because not every idea, no matter how novel it might seem in the beginning, is worth the work it takes to create an app.

How do you judge your app idea to see if it's worth pursuing? Ask yourself who would want to use it. If it can solve someone's problem, then it could be a winner. A problem-solving application that will be used by a specific group of people is the best scenario. If you can't find a target group of people who would find it useful, then it's going to be tough to market.

It doesn't have to be a brand new idea to work. If you're taking something that exists and improving it, then it could be a good idea. Apps that engage people through interaction, like games, and even humor are also good possibilities. One last test is to see what's out there that's similar to yours. If there's a popular app that's the same and you can't improve on it, you're probably wasting your time. Also, look at successful apps and note how they work, how they look and any things they have in common, so you can incorporate those principles into your own iPhone app.

If your iPhone app idea passes your "good idea" test, then you'll want to make sure, before you sink any money into development, that you're familiar with the iPhone and iPod Touch. If you don't have one or both of these, then you could be way off the mark with your idea about what people will want to do on their iPhone. Even if you're not a programmer, you need to be intimately familiar with these devices to really map out your idea. Imagine someone with no computer coming up with an idea for a program--know your medium.

Next, get specific. Write down exactly what the app should look like and what it will do. Make drawings of the graphics and screen layouts. Detail every step and screen in the process as much as possible. At this point, you'll know if your project is a go. If it is, you'll need to pay $99 to join the iPhone developer program so that you can eventually upload the app to the Apple App Store. Then either design the app yourself, or hire a good designer. Once you're satisfied, the next step is programming. Be sure to use non-disclosure agreements with anyone you hire.

At the end of this process, you'll have a completed iPhone App, ready to be submitted to the Apple store and promoted.