The front squat focuses more on your quads than anything else. Now if you back squat and never front squat will your quads be lagging? NO!! Actually I never front squatted until recently, and am looking to go for 405 for a single soon. All because I can back squat 515. The only reason I use the front squat is because I am looking to get into olympic weightlifting (already do powerlifting), and the front squat is a sport specific exercise to weightlifting (also to crossfit).
So if you are a crossfit athlete, you should front squat, but make sure you do it AFTER you back squat. Back squatting is actually even a better way to develop your front squat than front squatting! So just do your working sets of back squats, then do the front squats afterwards. I suggest doing 1 leg day a week, doing 3 extremely hard all out 6 rep sets of back squats. Then do the olympic lifts, then end it with front squats. Generally you want to move from heavy to light. Now you are probably thinking that the oylmpic lifts are lighter than the front squats, so why not do the oly lifts last?
Well the oly lifts are a higher priority and even though they are lighter, they are actually more taxing than front squats due to their unique requirement of power along with the axial load placed on your body.
So if you are a crossfit athlete or just are curious about the front squat, check this video out to see proper form. But be sure one thing... you can NOT drop the back squat!