Your friends list is saved on this device/browser (no login needed).
How does the Friends list work?
Add a friend: On the leaderboard, click the star icon next to any entry's name. It turns yellow when added.
Filter the leaderboard: Click Friends Only above to show just your friends on the leaderboard. Click Show All to go back to the full list.
Remove a friend: Click the star again on the leaderboard, or use the Remove button in this list.
Your friends list is saved to your device — no account or login required.