I have been using Close5, OfferUp, Wallapop and 5miles, local Facebook yard sales and Craigslist to sell of furniture. Things ranged from a $500 sectional to $15 DVD stands.
I still have had the most success with Craiglist. Because most of these were bigger items people had to come to my house to get them. It is still creepy to give a stranger your address but so far it has been ok. Dh is always home and I text my neighbor that someone is coming. So far it has all been quick and easy.
The few things I have sold on Close5 worked out well. This opens up a chat so you do not have to exchange any info at all unless you want to. The other apps don't have a ton of users yet. People also sell the most random things.
For all of these, including Facebook yard sales, list things higher than you want because everyone will offer less than your listed price. We listed a large sectional at $600 knowing $400 is what we really wanted for it so we got that at the end.
It is also strange that people will message you about an item and then never contact you again. Then you have to deal with a meetup time too. It is sort of a pain but we actually sold a lot more than i thought we would.