A real magic bullet is made of ice and leaves no trace but water in a corpse....
Magic Bullet Looks is a great tool to get certain (film)looks. A lot of presets, but also a lot more parameters you can use yourself. It takes some time to get to learn it all (I'm still no expert, but I knew the previous version very well.... a lot has changed). Using presets and tweaking them is my favorite way of using it.
If you use Premiere or another NLE without standard colorwheels to colorbalance, Magic Bullet Colorista is a great tool to grade your video quickly. (But mind you: no presets here!)
It also allows you to quickly add retangular or ellipse masks (with optional keyframes, feathers and inversion, but no freeform masks) to add gradients or highlight, darken, (de)saturize, change whitebalace, color, etc on only parts of the screen without leaving your NLE and even without using multiple layers.