Unfortunately Apple and Google do not cooperate at all with apps – and as you know they sell the apps and get the money in the first place – we just give the app to them and get some share for the sold ones.
So they handle the complete app selling process and we cannot unfortunately return or exchange any app for that reason – we have tried but there is no possibility for us to help.
I am very sorry for that but this is the case for any app store on the internet like that.
Moreover Apple (iOS) wants to work with a WiFi connection and Google (Android) prefers the connection with Bluetooth or cable. This is why another purchase of the app is necessary.
But once the app has be purchased for Android, you can use it on as many Android devices as wished without extra charge. That is really positive. You just need to log in with the same user login that you originally purchased the app with. The same is applicable for iOS. If you purchased the app once, you can download it on as many iOS devices as wished.
With iPad please check iPhone Apps in the App Store. This way iPhone apps will be found too and you can download Carly to your iPad.