I've tried a few different home inventory apps, and Under My Roof is by far the best. It's easy to use, easy to customize, has a clean & simple interface.
I got into it when I realized I needed to inventory my belongings for insurance -- I wanted a good and reasonably complete list of what I owned, so I could determine replacement value and make sure I had enough insurance coverage. Though I live rather simply and frugally, by myself in a small apartment, I soon learned I was underinsured. UnderMyRoofHomeInventory lets me list what I own, as well as upload photos, receipts, and user manuals, which sets me up pretty nicely should I ever need to make a claim due to loss. I especially live that I can set items up to hold other items, like my china cabinet and my storage totes. They each get values, photos, and receipts, and then I can catalog all the other items they hold.
The only thing missing for my use is expiration dates. Along with the usual furniture, clothing, electronics, etc, I'd love to be able to catalog and track consumables -- like the large stash of batteries that have gotten me through some extended bad weather/no power events. While I can add a field for expiration dates, there's no way to easily view expiring items, so I'm having to use a not-nearly-as-good pantry tracking app for those things.