Do you have any Android client recommendations?
I cannot find the option in Amethyst.
Discussion
If you tap on the sparkle icon in the top right corner it opens your list of relays. Whether a relay populates your global feed can be toggled by tapping the tiny globe icon next to the relevant relay.
I am also using Amethyst. 😉
To actually view the global feed, tap the magnifying glass icon at the bottom of the screen.