Unfortunately, at this time, iOS 8.0 is the oldest iOS version that we can support with new releases due to Apple's guidelines.
Apple typically only supports the current and previous iOS versions, and recommends that users stay current.
If you have an older device that cannot be upgraded to at least iOS 8, and if you need to reinstall the app in the future, you should be able to download a compatible version for your device:
1. Launch App Store app
2. (iPad) Purchased
3. Find Dr. Seuss Treasury in the list and tap the cloud icon to install
After you reinstall Dr. Seuss Treasury, you may need to use the Restore feature to reactive your purchase:
1. On your device, open Dr. Seuss Treasury
2. Tap on the Subscription button at the top of the screen.
3. Tap on the blue “Restore” button in the lower center of the Subscription page, and then swipe past the parental message
4. If it asks, enter the same Apple ID you used to purchase your subscription originally.
Note: If you use Family Sharing, then please enable "in-app purchases" before trying the Restore feature. You may disable in-app purchases after the Restore is complete.