Nice puzzles, but in app purchase doesnt go to all my devices

Seems a little ridiculous that Im supposed to purchase the unlock for each of my devices!?! Shouldnt I purchase it once then have it work on my phone and iPad?

GiGi1985er about My First Puzzles: Alphabet - A Free Educational Puzzle Game for Kids and Toddlers for Learning Letter Shapes - Kid Toddler App, v3.1