Steps to reproduce:

1. Go to https://wordpress.github.io/gutenberg/ using an Android device.
2. Tap on the (+) menu at bottom left.
3. Try to tap on "Paragraph" to start a new paragraph.
4. Try to tap on "Image" to tap a new image.

Result: the controls to add new content blocks seem unresponsive. (19s)

Tested with Chrome on a Pixel with Android 7.1.1.