At 13 years of age, Mercer Henderson had already created apps and was exploring ways to connect her work with nonprofit causes.
In October 2016, Forbes profiled Henderson as the founder of 4GirlsTech and the creator of Audiots, an app that added sounds to emojis. The profile also covered FriendIts, her second app, which allowed users to create private communities to share and swap clothes, accessories and other items.