Startup Idea: Software for Efficient Space Management in Laptops

Startup idea to develop a software that helps in identifying unused files that are occupying significant space in laptops, particularly designed with MacBook users in mind. The solution could also potentially prevent unnecessary files from being saved, allowing users to better manage space on their devices.

Im a college student with a 128 gb mac book pro. I love the computer but it has filled up fast. I try to delete unused files but I cant seem to find any of significance. I would recommend developing a software that finds and presents files or groups of files that take up valuable space. The software may also be able to stop pointless files from being saved on the hard drive?. Clean my Mac, very expensive, questionable at best. Right now I have to save all files to the cloud.