Firefox Rocket is the lightest and fastest web browser for Android. It has a Turbo mode which blocks tracking ads. And if you want to save more on data, you can enable image blocking while you browse. Tracking Protection prevents your browsing data from being collected or tracked by most websites/advertisers. You can save the whole screen to read offline with a single tap on the toolbar, save your cache and downloads straight to an SD Card and also download multiple files at once in the background.