Setting your soundcloud username
This is probably the trickiest part of using SCD, but once it's done, you won't have to change it again! Head over to soundcloud.com and log into your account. Then you'll need to go to your profile. Now have a look in the URL bar of your browser. Copy the last part of the URL and paste it into SCDs settings.
If you'd like to have it a bit more detailed:
SCD will now only download new songs you favourite/like on soundcloud. Contact me at firstname.lastname@example.org if you'd like to download all your favourites from soundcloud