Fits text on most web pages to the width of your device, without breaking page layout. WebViews and Chrome on Android used to provide this; I'm unsure if Firefox ever has. Opera still has quite a good implementation. For best results, set your text size to 'Tiny' to have pages look like you'd expect on a desktop.
This implementation is based on CSS/JS, thus I'm quite surprised that it currently works as well as it does. Please report any broken sites to me as I'm sure there are many out there.
