Check your sperm swimmers using the YO Home Sperm Test, a new, innovative app that turns your smartphone into a testing device for assessing motile sperm concentration (the number of moving sperm). Having motile sperm is a good sign of male fertility. Motile sperm are the guys that really count if you are trying to get pregnant! That's right, the word here is MOVING. Aren't you curious to see an actual video of your sperm AND to find out if you are in the "NORMAL" range? YO does this.