Bookmark icons and Apple Touch icons

The favicon has been around since 1999 as a 16 pixel square image in the .ico format. Although it can now be provided at a size of 64 pixels square, it's function remains the same. It appears next to a web page's page title on your browser's tab or alongside the URL address of a web page within your browser's bookmark system. If you don't have a custom favicon image provided for your website, your browser will provide a default image.

This is how the favicon for this website shows up inside my copy of the Google Chrome browser:

Browser tab with favicon next to the page title

A browser bookmark showing a favicon

With tablet computers, this gets a bit more interesting because they can display larger versions of these images. This is especially true for iPads and Retina devices with high-resolution displays. To satisfy these devices, a bigger selection of images needs to be added to the website. Here are the ones that I've used for this website:

Website bookmark icons - names and image sizes
The filename of the image The image
favicon.ico A website favicon at 64 pixels square
apple-touch-icon.png (the default image) The deafult 57 pixel square Apple icon
apple-touch-icon-57x57.png As above with pixel count embedded in the name
apple-touch-icon-72x72.png The deafult 72 pixel square Apple icon
apple-touch-icon-76x76.png The 76 pixel square Apple icon
apple-touch-icon-114x114.png The 114 pixel square Apple icon
apple-touch-icon-120x120.png The 120 pixel square Apple icon
apple-touch-icon-144x144.png The 144 pixel square Apple icon
apple-touch-icon-152x152.png The 152 pixel square Apple icon

Here are a couple of screenshots of the desktop of, first, an Apple iPad and, second, a Google Nexus 7, showing these particular bookmark icons amongst an array of other ones.

iPad bookmarks on the iPad desktop
Google Nexus 7 bookmarks on the Nexus desktop

All websites I build these days now come equipped with this type of image icon. So what sort of design would you like for your website's icon?