Added a tab bar at the bottom of the screen
On a phone and a tablet, four tabs stand at the bottom of the screen, under the thumb, in one block set in from the edges: Home, Discover, Notifications and the menu. The block has no plate of its own: what scrolls under it blurs, lightly at its top and strongly at the bottom of the screen. The count of notifications to read stays in view on its tab, and the count of messages on the menu’s. A tap on the tab of the screen you are on brings you back to its top; the menu opens as a sheet from the bottom, with everything the side rail holds on a laptop, Messages and Account included, your name at its head, then its entries as tiles four a row, the glyph on a square and the word under it, and under them the way to your other space and the sign-out, each on a row of its own. A touch lights the square alone.