eBay is an official app from the popular online auction and shopping website. It lets you do exactly the same things you can do on the official website. You can search for second-hand items, follow auctions and receive notifications, and of course buy and sell all types of goods.
The interface in this official eBay app is simple and intuitive. You'll see three main buttons: My eBay, Categories, and Sell. From the first one, you can access all the auctions and goods you are following, as well as other information about your account.
From the Categories button, you can search for almost any type of good. You can write down what you are looking for, as well as filter your search with very precise categories. Are you looking for a specific band's t-shirt? You'd start filtering by clothes, then shirts, etc.
From the Sell menu, you can manage everything that has to do with the goods you are selling, like pictures, descriptions, auctions followed by other users, etc.
eBay's official app is very useful if you use its services fairly frequently. On eBay, you can find pretty much anything.