The new version is not different in substance, so you can continue to use your old version.

In each update we will include the latest database of development times, and the new info accounts for less than 1% of the total listings. The app is already very mature and full-featured, so its hard to imagine anything else we can add, but we do listen to customer feedback and will improve it wherever possible.

It appears that if you are running v3.2 of the iOS software that the app does not show up. This is because the latest version of the app now requires v4.0 or higher. Older versions of the iOS may display the app, but you will need to upgrade to v4.0 or higher to run it. I'm not completely sure this is the reason, but from what we have been able to test, it appears that version checking is enabled on some devices, such as iPads running v3.2 (v4+ is due soon...)