Save
On a title page, + Add to My List saves it; the button turns into "In My List". Tap again to remove it.
Your list
The My List button at the top shows your titles as posters, then your episode marks with a link straight to the right season. Handy for following several shows at once, from Mirzapur to The Pitt.
Another device
Export saves a small file with your titles and marks; import reads it in another browser. Everything stays on your devices.