JSitor - Test your NodeJS, JavaScript, CSS, HTML online with JSitor code editor.
NeoDownloader - As you know, there is a lot of websites with a lot of pictures, music and movies.
CodePen - A front end web development playground.
Vov Picture Downloader - Download pictures from websites.
JS Bin - Sample of the bin:
Persepolis Download Manager - Persepolis Download Manager is a GUI for aria2.