If you purchased something through one platform (say iphone) would the app be able to transfer to the other platform (say i pad/android). I realised the scenarios I bought in my Iphone is gone when I start the app elsewhere, does it mean I need to buy them AGAIN?
I believe you can transfer between iPad and iPhone (both are through Apple's App Store). You might need to find a "restore my purchases" button in the app. I know when I moved to a new iDevice and tried to purchase content I didn't realize I had already purchased, it told me I had previously purchased the scenario and downloaded it for free. However, you cannot transfer between Android-Apple, Android-Steam and Apple-Steam environments.