A free app for Android, by ФНС России.

Проверка чеков ФНС России is a free application that offers a range of services for both buyers and sellers. Buyers can verify the correctness of their payment with a QR code from the check. Users can also manually enter the check’s details and request real-time verification from the Federal Tax Service of Russia. In cases where a violation is suspected, authorized users are able to submit reports that feature an expanded list of requirements. Additionally, users will be rewarded with bonus payments for participating in partner programs.

This is a useful tool for both individuals and businesses. Plus, the app is free and works with Android 5.0 and up.