Quickly swipe to switch tabs in Safari.
Safari's tab switcher is very pretty but all of its animations make it unnecessarily slow.
SafariSwiper lets you quickly switch between tabs simply by swiping left or right on the toolbar (the bar with the back/forward, share, bookmarks buttons) to instantly switch tabs.
Source code available at GitHub
Compatible with iOS 8.2 - 8.4 on all device sizes (though it's less useful on large devices which show a tab bar anyway).
Configure options from Settings.