It's simpler to buy-and-sell the appliances on craigslist. That way you don't have to worry about the borrower depreciating the value of the appliance or not returning it in a timely fashion.

Also, maybe I'm not in love with the ladder I have. Selling it for $20 so I can justify buying a $2000 composite one that fits in your pocket is a pretty good use case.

If I lived in a dense metro area and couldn't afford to store a full complement of tools, I could afford to hire people to perform the labor associated with those tools, so urban isn't even a use case for a borrowing app.

Borrowing is like bartering: a coincidence of wants is much less likely than a want of coincidences.