iPhone 4 and iOS4 app upgrade questions

Do you need the new app now, right away? If not, wait. There may be a better and newer choice in the same category two weeks from now. On the other hand, if it's something you've wanted for a while, and that you can use right now, go ahead and get it. Odds are any changes will be updated after the release of OS4 and iPhone 4.

You should watch Steve Job's keynote address at the start of Apple's worldwide developers conference last week, or if you already have, play closer attention when he discusses 3rd party apps involving the higher resolution retina display included with the iPhone 4.

App developers don't have to do anything different unless they want to. Per Steve Jobs discussion on this particular subject, if a developer does just a little bit of extra work, opens the hood of their app and ads higher resolution images/graphics, the app will look stunning on the iPhone 4, but the app will look great or better with the iPhone 4 without doing anything.

If a developer does as Steve Jobs suggested, it will be included with an app update.

On that note: will app developers be upgrading their apps to the higher res for free, or make new "iPhone 4 specific" apps.

For free. This does not involve re-writting the entire app, and there will not be iPhone 4 specific apps. All existing apps will be compatible with the iPhone 4 and will look better on the iPhone 4 than on the iPhone 3G and 3GS without the developer having to do anything.