Can I add my own activity types or change the icons?
Yes. Settings, Operations, Activity tiles lets you add tiles with your own name and icon, reorder them, and hide built-in tiles you never use.
Yes. The quickest way is from the logger itself: tap the star Activity tile, type a name, and tap Save as a tile. Any staff member can do that. To manage the full list, go to Settings → Operations → Activity tiles on the web dashboard (owners and super admins) or Admin → Activity tiles in the app (center admins too), and click Add a tile. Give it a name (up to 40 characters, for example Music and Movement) and pick an icon from the grid: a music note, alphabet blocks, a teddy bear, a slide, and dozens more. If none fits, you can use any emoji instead. The tile appears in the logger next to the built-in ones, on the web, in the app, and on the room tablet, and parents see its icon and name in the feed.
From the same card you can rename a tile, change its icon, reorder tiles with the arrows, and remove one. Removing a tile that already has entries keeps those entries' icon and parks the tile under Removed tiles, where you can restore it.
If there are built-in tiles your program never logs (Tummy Time, the therapy tiles, and so on), click Choose next to Built-in tiles and click the ones to hide. Hiding only removes them from the pickers; anything already logged still shows.
One thing you cannot do yet is rename a built-in tile or give it a different icon. The workaround is to hide the built-in tile and add your own with the name and icon you want.
Related: Add your own activity tiles.