For Mac users, we didn't need a program like we thought.
Just follow their instructions which were to copy the new files in the game folder:
1. Download the rpa file after purchase
2. Open the folder of your current Our Life Build and find the "game" folder inside. To view folders on Mac you might have to right click the application launcher and select "view package contents" and you may have to open a couple different folders before you find the "game" folder tucked away inside
3. Move or copy/paste the rpa file into the Our Life "game" folder