Yes the first bad thought is that it can be used to steal some facts of ones identity. The face, the signature (if signed) and the security code of the credit card.
Before using this app be sure to cover the security code and signature with white tape.
I received the same pupil distance four times in a row. You will have to be able to keep the card straight and at a good distance where your picture will also be straight.
Try it several times securely as I instructed above. Then go with the most common result.
As for the developers, I am sure if you store these images in a manner to involve identity theft. You will be tracked. And its all traced on the Internet.
It saved me a call to question my pd to the eye glass center. Thanks for developing a practical and helpful app.
Dont be paranoid about Pupil Distance PD Measure