The login allows you an access to more add on features. Other applications can only be used after logging in and after getting the permission per the service provider.
If you are not registered yet, just fill out the set form under "register". After that an E-Mail will be send to you with an automatic generated password which should be changed immediately after logging in the first time. This can be done under "Edit profile".
If you have lost your password, you can get a new one by demanding it under "lost password?".