Hello everyone !
I have made my best ever app in MIT App Inventor.
Name = Offline Credit Card Number verifier.
Version - 1
Price - $1
It just not verifies only credit, but debit card also.
Anyone interested, PM me for .apk or .aia.
Thanks to the extension developer @JEWEL
Link for the extension of @JEWEL - https://community.kodular.io/t/card-validator-determine-card-type-number-extension-free/120846
Thank you !