This update from Apple will improve the functionality of this app. No new features are included.

This new release provides a completely revised UI and user experience, making the application easier and more pleasant to use.
The user experience has been reviewed to be consistent  across all HT Designer applications, on all supported platforms.
The application is now taking advantage of all iPhone screen sizes.

Access to unit selection and speed of sound setting are now easily available from each tab (swipe down to reveal).

French version
Fixed tab ordering persistence
Fully tested with iPhone OS3.0
Improved help

You can now compute the modal response of a room.