GDPlayer is (GPLv3), but there is a "GDPlayer Pro" tier for $9.99 (one-time). Pro adds:
One of GDPlayer’s most significant contributions to the Geometry Dash ecosystem is his creation of "The Evolution of Difficulty" series on YouTube. These videos are not just compilations; they are extensive documentaries that chronicle the shifting landscape of the game’s hardest creations. By contextualizing the history of Top 1 levels—from the chaotic early days of Cataclysm clones to the modern, artfully designed "endless" difficulty levels—GDPlayer has preserved the game's heritage. He has educated newer players on the legends of the past, such as Riot, Sea, and SungMin, ensuring that the community remembers its roots. This role as a historian adds a layer of depth to his persona that few other top players possess; he is not just participating in the history, he is recording it. gdplayer