We currently have two versions available, so what's the difference?

When we originally made Sudoku Of The Day it was when there were only iPhones (and iPods).  When the iPad was released, it wasn't possible to make an app that would support both the iPhone and iPad together, so we released a second version for iPads, which had a higher resolution, so was named Sudoku Of The Day HD.

Over time, Apple allowed us to make a combined version, and so we added iPad support to the standard version, and iPhone support to the HD version.  If effect, both versions now look and work the same for iPads and iPhones!

It isn't currently possible for us to combine the two products together ( so that all customers can be on a single app! ), but we are encouraging everyone to move over to the HD version over time.   If you have a purchase within the standard version, please contact via the built-in support system inside the app, and we will provide you with a migration code to give you the same unlock in the HD version.