Google has uploaded the Material Design icons to Github.[1]

At a quick glance it seems to have all the icons we need, and already in svg format. There's even a toc icon[2]. I think we should consider switching to those for the Android app to be more in line with other Android apps.

Bernd

[1] https://github.com/google/material-design-icons

[2] https://github.com/google/material-design-icons/blob/master/action/svg/production/ic_toc_48px.svg