If you have a Web-based service that's accessible by any browser, then you've had the luxury of being able to deliver your service to Apple iPhone and Google Android G1 users from day one. Why then are so many developers choosing to go to the trouble of creating an iPhone or Android app?

If you're a service like Web-based IM leader Meebo, you build an app to enhance the functionality of the Web-based service. And that's exactly what they've done with Meebo for Android.

Using Android's ability to run multiple programs at the same time, Meebo for Android can deliver functionality that mimics more traditional desktop IM clients - allowing the app to run in the background and deliver real-time notifications as IM messages arrive. Ding!

Even more importantly, Android allows Meebo to deliver an application that can't live on the iPhone platform today. Why? Because of the iPhone's inability to run multiple applications simultaneously. "Running another iPhone application in the background" is a foreign concept - unless you're the owner of a jailbroken phone.

While glimpses of the Meebo app have been available for months, today marks the first opportunity for G1 users to download the app to their handset from the Android Market.

Meebo - which boasts traffic of more than 5 billion messages per month - continues to advance their service. This mobile offering marks another step forward in their continuing efforts to make the service more accessible to more people. The Android release follows closely on the heels of their Community IM partnership announcement which promises exponential growth in the number of Meebo users over the coming months.

And while the Android app might not increase the user base as drastically as Community IM, it's still a significant step in taking advantage of Android features that its closest competitor currently lacks.

These days, a number of developers seem to be building mobile apps simply because they can. Meebo for Android, however, avoids the pitfall of simply "reiterating existing services" by taking a step forward in augmenting Meebo's functionality using the Android platform.