Hey, I just added a mac version of the editor
1. First you'll need to move IM_Data folder into your ~/Documents folder
2. Your mods will be available here: ~/Documents/IM_Data/StreamingAssets/Mods/
3. To install a mod, find the game .app -> right click -> Show Package Content
And copy your mod's folder (~/Documents/IM_Data/StreamingAssets/Mods/*mod_id*/)
into Contents/Resources/Data/StreamingAssets/Mods/