Whatever else it achieves in offering observations about friendship and love in the modern age, Life Partners is definitive on one subject: the tyranny of the smartphone. The devices intrude on almost every scene—not as a way of making a point about our wired existence, but just as a part of everyday life. (One subplot involves texting while driving, and the minor fender-bender that results.) The characters are accustomed to having every conversation, flirtation, or seduction punctuated by the buzzing WHAAH of a phone vibrating its latest demand. No wonder they can’t concentrate long enough to straighten out their lives.