Using ltdsave.app
A walkthrough for non-technical users: how to retrieve your save files from Ryujinx, Eden, or a modded Switch, and how each editor tab works.
ltdsave.app documentation
A browser-based save editor for Tomodachi Life - Living the Dream. These docs explain how to use it and how its save files are laid out.
Save file reference
The binary layout of Player.sav, Mii.sav, and Map.sav, the key-hashing scheme, and a field-by-field reference for every known entry.
Documentation coverage
A live tracker of how much of the save file format has been documented so far.