youtube.png | youtubeplaylist.png
Author: Dakirby309
License: Free for non commercial use
https://www.iconfinder.com/icons/100115/alt_youtube_icon#size=256

vimeo.png
Author: suraj vibhute
License: Creative Commons Attribution
http://findicons.com/icon/450573/vimeo#

downloads.png
Author: Oliver Scholtz
License: Free for non commercial use
https://www.iconfinder.com/icons/23493/arrow_down_download_orange_icon#size=128

next.png
Oliver Scholtz
License: Free for non commercial use
https://www.iconfinder.com/icons/23498/go_next_old_icon#size=256

search.png
Frank Souza
License: Free for non commercial use
https://www.iconfinder.com/icons/79859/find_gtk_icon#size=256

recent.png
Oliver Frank Souza
License: Free for non commercial use 
https://www.iconfinder.com/icons/79728/folder_recent_icon#size=128