If you have a need for system icons and don’t want to create your own (or, like me, you have no artistic skills), you might want to look at a recent Google Design set that is now open source:
Today, Google Design are open-sourcing 750 glyphs as part of the Material Design system icons pack. The system icons contain icons commonly used across different apps, such as icons used for media playback, communication, content editing, connectivity, and so on. They’re equally useful when building for the web, Android or iOS.
