Ranked in these QuestionsQuestion Ranking
Pro Designed under Material Design guidelines
Pro Open source
The icons are open source and free to use.
Pro Hosted by Google Web Fonts
As with any font hosted by Google Web Fonts, it's simple to use. Self-hosting is available, or you can include a single line of HTML.
Con Some icons look ugly
Con Small set of icons
This font contains rather small set of icons that are targeted to be used in context of mobile device.