As of the new release made in mid August 2017 the Android app is currently approx. 60mb in size.
The iOS version is approx.. 80mb in size.
The large size is due to the amount of images that are included in a few different size formats – one large version and at least two other versions to best suit various screen sizes.
The app can be used without an internet connection. The pictures and data are always there and can be viewed from anywhere in the universe!
The Check Your Change admin is Mr C H Perkins, publisher of numismatic publications in printed and eBook format. Author of "Collectors' Coins - Decimal Issues of the UK" and other books on British coins and related subjects.