I just downloaded Geometry Dash off Google Play and I'm very happy with it; it's worth the money just from how fun it is playing the levels. But I'm also interested in making my own level using the Level Editor, though the problem is that I want my level to use a custom song instead of the songs in the game. Is there any possible way to upload and use my own custom song?
Go to www.newgrounds.com, find a song, copy the last part of the URL at the top. That is the ID for the song. Next, go into the level editor and tap on the cog in the top right. Then, tap the custom button, and hit "New". Finally, type in the ID you copied into the text area that says "Enter song ID".