Yes, use of the app is free. Users can mark coins as got, change the quantity they have and also record a short note for every coin. The app is completely free of advertisements.
There is an option to ‘upgrade to premium’ which when purchased reveals current market values for all the coins in both used and as-new condition.
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.