https://blendermarket.com/products/bool-it

Bool it is a a quick way to apply booleans in object mode and manage them. Cool for beginners who wants to create hard surface style modeling without loosing their mind :) . Can save time for others …Hard surface modeling is a complex process. They are many addons that are great for advanced users, and do a very great job for that… And you know, the edit mode of blender is so powerful that you can create complex structures starting from a cube !

 

But for beginners, sometimes it can be a little frustrating to spend hours understanding menus or learning the shortcuts to create simple shapes ( in fact, like me ).

 

Bool it is a fun addon that helps you manage booleans easily, and mimic hard surface modeling . With only union and soustraction, the idea is to arrange your blocks / parts in the viewport in object mode and select wich part is positive or negative.