ECHO
One cave a day. Ping it, read the counts, find every moth in the fewest pings.
A dark cave, a few moths hiding in it. Tap a spot to ping: a ring spreads and a lantern is left there with the number of moths inside the ring. Hold a spot to mark it as a moth or as empty, your own notes. Mark every moth correctly and you are done.
One a day
Everyone gets the same cave. Monday is a small one with two moths and Sunday is the largest, with more moths and wider rings. When you finish, Copy gives you the day number, your ping count and a row of rings. It shows nothing about the cave.
Credit
The ring that counts what it holds owes something to Minesweeper and to Battleship; the cave and the lanterns are Freetail's. Nothing you do is sent anywhere, and there are no accounts, ads or tracking.