In May 2018, as the GDPR takes effect, EU would be setting forth stricter privacy guidelines. After it comes into effect, your app users may approach you with a request to access, edit, or remove any personal data that may be stored on your app. It is important that you comply with the GDPR requirements, and for that it is our suggestion that you make yourself better aware of the guidelines and understand its impact on your app.
If a user, in particular an EU citizen approaches you about their personal data, here is what we suggest you do.