This app is so under-rated. For years I always feel uncomfortable using a .pkg installer on MacOS. For one it asks for root password upfront, and two what is installed where is purely opaque. I always wonder what happens behind the curtain.
Suspicious Package solves it all! It's a inspector for .pkg file. It tells you what file will be installed where BEFORE you actually run the installer. It also shows you all the shell scripts that will be executed, so you can vet them thoroughly if you want. And all this awesomeness comes for free!
Definitely recommended for anyone cares about security.