From OLX, you can buy and sell practically anything, from a box of books to an old phone you no longer use, to various projects or services or even a home or a vehicle. The good thing about OLX is that there's no middleman, so all the agreements reached are between the buyer and seller only.
By default, OLX finds your location and offers only listings near you, but you can also manually change the country to show ads from around the world or for a particular place.
OLX is an interesting classifieds tool for buying and selling all sorts of things. It has a good number of users and a simple and attractive interface through which ads can be published in a matter of two to three minutes.
Requires Android 2.3.3 or higher