Like many other yoga enthusiasts, Billie Whitehouse sometimes struggles with her form. "I never know if I’m doing it right," she says. "I always love it when the instructor comes and corrects my form." But yogis practicing alone in the comfort of their living room are left to figure it out for themselves. Whitehouse, the cofounder and CEO of technology company Wearable Experiments, realized she was in a unique position to bridge the gap. So she and her cofounder Ben Moir created Nadi, smart exercise tights that correct a wearer’s alignment using haptic feedback in the form of subtle vibrations. From the outside, the Nadi tights don’t appear particularly high-tech. There are no wires or gadgets protruding from the fabric.