His eyes widened along with his smile as he asked me, "Do you have the Yo app?" When asked why people should want to save Yo, cofounder Or Arbel told Mashable, "They shouldn't. Unless they use it ...

He envisioned a simple app with large buttons that, when pressed, would send a one-word notification to another person: "Yo." The "Yo" would let the person know they were needed or being thought of.