This is a trick that many people have asked me about. What some Snapchat users do not know is they have they ability to write in black or white. When you select a color on Snapchat you can hold down on the color palette on the left and then slide across the screen. As you slide across the screen you will see the color change on the pen. If you slide all the way to the bottom of your iPhone or Android you will get black. If you slide all the way to the left you will get white. Here is a video on how to do it:
What do you think? Will you use this black and/or white pen in the future?