Bobby - Keep track of your subscriptions
WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
Rocket Money - Find your paid subscriptions and cancel with one click
WizTree - WizTree quickly finds the files and folders using the most space on your hard drive. It scans the MFT (Master File Table) instead of crawling the entire disk which makes it very fast.
Billbot - Track your subscriptions & recurring expenses with ease
SpaceSniffer - SpaceSniffer is a freeWare (donations are welcome) and portable tool application that lets you understand how folders and files are structured on your disks.