guitarLayers - guitarLayers is a professional macOS guitar learning software.
Sertifier - Best way to send smart certificates & open badges!
Fachords - Fachords is an online site that provides many resources that you can use to take your guitar skills to the next level.
Certopus - Design & Deliver verifiable certificates
TrueFire - The Best Guitar Lessons Online Fast. Easy. Fun.
Certificates by Graphy - Certificates by Graphy lets you share beautiful custom certificates to all your learners at once.