Navy seals abs workout
 

Looks like a decent workout, no equipment needed.

Just a note of caution though. Don't fall into the trap of working just your abdominal muscles. It is extremely important for current and especially future health to work the LOWER BACK muscles.
If not you will get problems such as terrible posture (your ab muscles will pull your body, especially shoulders, forward causing a far more slouched posture (the opposite of confident).

;)Yeah neglecting any muscle group is a bad idea.

This workout is superb to get the ab quickly and easily as compared to any equipment or supplements,.Its really better way to get abs,.