A better mix of puzzle difficulties

In version 1.55.0, the puzzle generator delivers puzzles with a better mix of difficulties. The changes in detail:

• When the difficulty weighting for the puzzle generator is set to "random is fine", the puzzles are now generated with a much better mix of difficulties.
• In Normal play mode, the puzzle generator now only generates puzzles up to a difficulty level of DIFFICULT (and not up to VERY DIFFICULT, as previously). As always, the play modes Advanced and Expert can be used to generate VERY DIFFICULT puzzles, if required.

This is expected to be the last release to include support for iOS 14. To benefit from future updates of the app, please be sure to update devices still running iOS 14 to a more recent version of iOS.