Hi Kaat, Mccdelc and Catt11 I'm sorry to say that as of now my husband has no plans to bring the apps to Android. He has a full time job that has nothing to do with app development and he develops the apps in his spare time. We also have a little baby girl that takes a lot of our time. He always hates telling Android users no, but he really just doesn't have the time or resources to work on other platforms.
He is currently working on major updates to both TieredCaker and SheetCaker that are very exciting! After that, he will continue with new apps that are planned for the Calculated Cakes suite.
I'm sorry this is probably not what you would like to hear, but I hope it helps explain why the apps are only on iPhone, iPad and iPod Touch devices.