At the other hand WhatFormat knows more extensions, because not every format can be recognized by the first bytes. WhatFormat is shareware. If you like this program and decide to keep on using it, then you must register. Registration motivates me to make newer versions of WhatFormat. You can pay by pressing 'Register' in the 'Help' menu.
Registration is easy and there is a variety of payment options, including credit-cards and cheques.
Your registration will be securily handled by the Kagi service. After I've received your details from Kagi, which should happen immediately after your payment, I'll send you a registration code by email, within about 4 business days. The registration code will remove the nag-screen you seen on startup. Your registration is valid for any future version of WhatFormat. Peace of mind.