4. letgo
Google Play Rating: 4.4
iTunes Rating: 4.5
Sometimes you have to let go of stuff you don’t use, and letgo will make it happen. The app has tens of millions users and it is growing rapidly. After you set up a profile and snap a picture of your item with an in-app camera, letgo will automatically recognize the item and do all the categorization for you. You just have to name your price and wait.