When it comes to developing apps, there's no doubt that you need to do more than just serve iPhone or Android. There are lots of different platforms and you need a way to target customers on each one. Research your customers' needs and provide a solution that works for as many of them as possible. Your potential customers probably use a wider range of handsets than you would expect. But coding natively for Android, iOS, BlackBerry, and all the rest can be a real chore - and it's very expensive. It's often worth looking at cross-platform solutions which will allow you to write your app once (usually in HTML) and then port it easily to different phones. We're very impressed with Tribal Labs' Cross Platform App Development Report. It covers 22 different application development frameworks, including Grapple, PhoneGap, Titanium, and Sencha Touch.
If you're thinking of writing an app and know that your customers are on a wide range of platforms, this report is essential reading. It's a great overview on a complex subject. At InMobi, we'll quite happily serve adverts to your native app or to your mobile website. We even have an API so if you want to serve mobile adverts on a PlayStation Portable or an Internet Fridge, you can. Our adverts are designed to work on a wide range of phones - and we're working hard to make sure that our tools work with a variety of frameworks. If there's a particular framework you use which you think we should be concentrating on - leave a comment or send me an email.