To hone is to sharpen a knife or perfect a skill. Home is where you live, where your stuff is, is where the heart is, and all that.
Hone in or hone in on, is an eggcorn for home in on. (An eggcorn is a word accidently used for another word that sounds similar, like saying eggcorn instead of acorn.)
Home in on (with an "m") means to move toward an object or goal, like a missile zooming towards a target. Or as a homing pigeon does, which is where the term comes from. Here are some examples:
Another international e-commerce site that has homed in on the Brazilian market is farfetch.com. (New York Times)
Bedbugs are active at night, leaving their hiding places to home in on body warmth or carbon dioxide to reach their victims. (Monsters and Critics)
Hone is to sharpen something, like a blade or your attention in math class. The only reason people get it confused with home is when hone horns in on home in.
Although you can make something pointy by honing, when you try to hit a target, you home in on it, like going home after a long day.