Actually, in some states, to record conversations, two-party consent is necessary. 11 states, including California, require two-party consent. It’s a fair assumption that an app that is vacuuming up everything someone does on a phone is potentially gathering data that would fall under two-party consent laws. Also eavesdropping is also a potential crime under common law. It’s a murky legal area in this case, but one that certainly has some merit.