The Urban Dictionary is a free online tool that allows you to look up the meaning of any word, phrase, or sentence in English and other languages. It is created and maintained by a team of people who are always looking for new words and expressions to add to the database. 

This tool is an online dictionary. It means that the app does not require you to download anything. All the information is available online. The team creates and maintains the database by adding new words and expressions and marking them as correct or wrong. 

The app also incorporates the possibility of sharing the definitions with your contacts. This is a free online dictionary, and it can be used on the web and on mobile devices.