iPhone dev Stupidity 86: Upgrade - how to import old data

1. How the upgrade works: 

"Upgrades replace the app bundle, but anything else in your sandbox (like the Documents folder, caches, preferences, etc) are preserved in place."

2. How to importing/exporting app data:

"I think the short answer is yes, the only sensible option are webservices. There is no iTunes sync plugin that you can use so your options are all network based.

Other than webservices, you might also like to consider a client-side program that your iPhone app finds and connects to using Bonjour. The obvious disadvantage here is that you have to write client apps (preferably two, one for Windows the other for Mac) and educate your users on how to download and install them. Also you're forcing your users to sync using WiFi."

3. How to test upgrade:

"I think testing with AdHoc versions that is dragged dropped in iTunes is a similar upgrade situation.

That's how I tested upgrading our Chess game, so it keeps old and current games on the device.

As for the files/DB I suggest they should contain some version number."

4. Lite to paid app data migration:

Using IPC (openURL with Base64 encoding) to send data from Lite to the paid app.

5. Some details on iPhone IPC