Simple-saurus Rex (a Google game)

Some people brighter than I am may have realized this a long time ago, but I only recently discovered this Google gem. When you're offline, if you hit spacebar (or tap for mobile) your dinosaur springs to life and begins running through the desert, and you must jump over the cacti or suffer a terrible fate (death). Simple, but entertaining while you're waiting for signal to come back and that pesky page to load.
If I were of the talented sort, I would make a gif, but alas you're stuck with a crummy phone screenshot.

Cat tax