Before trying to reset your password in case of login failure, please assure your device is set to correct date and time. A device with incorrect date set, will be perceived as an "untrusted" device, therefore login will fail.
To retrieve and reset password, go next to the login/register section and you will see "Request new password" or visit the direct link: http://slideme.org/user/password from your web browser.
You will be asked either your email address or username you used to initially register.
Next, an email will be sent to your email address with a link, for you to reset your password to any password of choice. Always assure you make note if you used uppercase or lowercase characters in your password.
If you have not received an email to reset your password, check your spam mailbox. Otherwise it maybe that you entered an incorrect email or your email provider has not relayed the email to you. Assure you whitelist emails from SlideME. Only if problems persist, contact SlideME Support.