This business model sells a companion application (an external software installed on your PC/Mac) that works with the free extension. Paying provides a unique License Key that unlocks:
Easily convert video streams into standalone audio files. Video Downloadhelper License Key
Licenses are tied to your specific installation but can generally be transferred. If you switch from Firefox to Chrome (or vice versa), you may need to re-enter your registration code within the new browser's extension settings. Invalid Key Errors This business model sells a companion application (an