During the registration process for the App, you can use the 'Forgotten your Membership ID' or 'Forgotten your Password' options and then follow the instructions.
Alternatively, you can visit Secure Trust Bank's Internet Banking portal and use the 'Forgotten your Membership ID?' or 'Forgotten Your Password' options.
If you have forgotten your App PIN, simply use the 'Reset PIN' option shown on the Passcode screen in the 'Menu' and follow the instructions.