About Tydlig
Tydlig is a new kind of calculator for iPad and iPhone that sheds the legacy limitations of old devices, for a truly modern experience. You can also check it on their website: http://tydligapp.com/
How to get it?
Firstly, you need to download "Apple Store" app on your iphone and ipad;
Secondly, go to "store"(at the bottom)—>"Find a store"(at the top)—>"All stores"—>"United Kingdom" and choose any store;
Then, click the third one to download, enjoy it!
The deal is for any itunes account including Australia account.
Also, thanks to @uradox, you can get "Bicolor" code at any Japanese Apple store
https://itunes.apple.com/au/app/bicolor/id795688887?mt=8
Price shows as $1.99. Not a free …