Mac App Store edition of DaisyDisk has a few less features, in order to comply with Apple’s app submission policy. Mac App Store users can get these features free of charge by installing the standalone version of DaisyDisk along with the one they purchased from Apple.
No, it's built from scratch. The original design has been inspired by Scanner 2 app by Steffen Gerlach.
We'd rather go with a simple product which does a single thing right than an app with lots of features that may or may not work. If you prefer features over quality, try WhatSize. We also do not believe in “clean your system in one click” tools: there's no magic bullet.
Have a Mac running OS X 10.5—10.9? Choose your legacy version of DaisyDisk. They’re no longer updated, but may be really useful for keeping older hardware in better shape. Need a legacy license? Just contact our support team.