I can too now. Last night, when I did this lesson, there were no hover translations on this sentence alone. I did once have a lesson on my phone that did not have any hover menus at all, but this is the first time they failed on only one sentence for me. Just a vagary of the software, I guess.
This is a fixed expression used unchanged over years. "Ακόμα" adds emphasis to the idea of boundlessness but is not linguistically needed.
However, we do have alternative translations which include: "even beyond, still beyond, still further, further away, yet beyond, yet further".