Oer dizze útwreiding

Adds Geometry Dash functionality to the Newgrounds Audio Portal using the GD Browser API (gdbrowser.com).

Features:

Shows a song's usability in GD in the Licensing Terms.
Shows GD levels that use the song in a box with links to their GD Browser pages.
Usable songs have a button to quickly copy their Song ID.

Wurdearje jo ûnderfining