Indispensable I've used this app for ages and it's a vital part of power user phone management. Knowing at a quick glance what is taking up the most space on your phone may surprise you. I've had situations where camera got switched to internal storage randomly  or rogue apps get an ever increasing cache (I'm looking at you download manager!)  etc. Without an app like this you might never notice. It's great and easy to use. I get everyone I know to use it.