Buy once, use everywhere

You know something about apps. I hate that running multiple (and competing) platforms, you as a customer lose.

I don't want to spend money on the exact same service to run it on competing platforms. This is something where the HTML5 apps can make a huge dent to the current app eco systems.

Develop once, sell everywhere and as a customer, you only buy once. That is ripe for a certain subset of apps. If you're not already thinking about this as an app developer, you should be.