When logging in, you will be asked to enter an authentication code that will be sent to your registered e-mail address. You cannot log in any other way.
If you do not see any e-mail addressed to your registered e-mail address, check your spam folder, filter, tab, etc.
Unfortunately, if you don't have access to the account's e-mail address, we are unable to continue troubleshooting. While we understand that it can be disappointing when you lose access to an account, we use these authentication requirements to make sure we don't give out any user information to the wrong person.
We do not currently provide apps for Android and other platforms. About the app for Android, we are considering providing the service in the future, but we have not decided when to start the service.