Purchasing the Essentials on iPhone allows you to use Concepts on any iPhone, but will not unlock the Essentials on iPad. To unlock Concepts on iPad you simply pay the difference in price. You will be prompted upon checking out that you’ve already purchased Concepts for iPhone, and will only be charged for the difference between the iPhone and iPad versions.
 
If you purchase the Essentials or Subscribe on iPad, you have access to Concepts on any iOS device. In addition, our free Concepts account syncs your purchases, objects and palettes across devices.