Let’s dive a little into the guts of our iPhone to discover one of the (dirty) tricks used by Apple’s own applications to give the feeling of charging faster than they actually do. How? You may ask. Each iPhone application includes a “default.png” image that is displayed when we run it before starting any other process. The idea is to offer a screenshot of the initial screen of the application that is replaced by this one when it finishes loading.
This is why applications like Contacts or Mail don’t respond right after they are launched. Some applications like the ones mentioned above can update the image to match the content of the image (contacts or mail) while third-party applications only show an empty template that is filled in with the data when the upload is complete or a welcome screen (e.g. Twitterrific).
You can verify this arrangement for yourself in many ways but one of the simplest is to modify your contacts without using the iPhone application, for example, by adding or removing a contact whose name should be listed first in the Address Book and synchronising the phone. When you try to see them on the iPhone you will see that the new contact does not appear until a few seconds later than the rest.