Hi sir! The Philateler is a menu collector for collecting exclusive stamps that are released with each action update (The Philateler is in the main menu). You will unlock Mumu and also Mimi (for Mimi you need to collect 5 stamp sets). They both will help you make the game easier. You can get stamps for The Philateler on my Patreon!! Thank you, I hope this helps ^_^.