Brackets + Chrome + Ripple (plugin) great for kids
I have just introduced my students to Brackets (as the editor) and Chrome + Ripple for developing HTML/CSS/JS.mobile apps (and bog standard websites). Brackets allows the students to see the structure of their folders (and code hints for hrefs etc saves a lot of grief :-) and having images "lightbox" in the editor to make sure you the right one is valuable ).
Nice integration - Ctrl+Alt+P opens Chrome & a mouse click then opens the Ripple android/iOS emulator (lots of different screen sizes to play with) , and it is live emulation, change a css property or html element & you see the change live - without having to save & refresh (again something students struggle with remembering). And from within Brackets you can open the chrome developer tools with a function key.
(Adobe & Google - who would have thought of me recommending that! combination)