Harvard student Ben Yu gets jittery, then crashes after drinking a cup of coffee. She he invented a sprayable caffeine that offers a consistent level of energy without the jolting buzz-then-crash that can come from caffeinated beverages. The colorless, odorless spray comes in a slim pocket-sized bottle containing 40 doses. One dose (4 squirts) on your neck offers about the same effect as a cup of coffee. It sells for $15 exclusively through Sprayable.co, though the goal is to get it in gas stations and convenience stores. To Yu’s surprise, it took only 24 hours to raise start-up funds via Indiegogo.