Many of the movements in the our stretching database do not require any equipment at all. If you have your body, a wall and the will to get into positions that hurt a little now (so you can feel great later), you can do mobility. That said, sometimes a foam roller and a massage ball will do wonders to help you move through the basics.
With that said - there's a ton of interesting and useful mobility tolls that have come on the market in the last few years.
Check 'em out.