guitarLayers - guitarLayers is a professional macOS guitar learning software.
Sertifier - Best way to send smart certificates & open badges!
TrueFire - The Best Guitar Lessons Online Fast. Easy. Fun.
Certopus - Design & Deliver verifiable certificates
Gitarrero Beginner - Gitarrero Beginner is a multi-featured, and easy-to-use guitar school developed as a guide to help you learn guitar skills and play them comfortably.
Certificates by Graphy - Certificates by Graphy lets you share beautiful custom certificates to all your learners at once.