David Smith

David Smith — often called "Underscore" after his X handle — is one of the longest-running independent iOS developers, building apps for Apple platforms for around 18 years. He is the creator of Widgetsmith, Pedometer++, Sleep++ and Watchsmith, which he develops on his own under his company Cross Forward Consulting.

His career is a textbook case of an overnight success years in the making. After more than a decade of shipping dozens of apps, he launched Widgetsmith alongside iOS 14's home screen widgets in 2020. Thanks to a wave of TikTok home-screen makeovers it shot to number one on the App Store and stayed there for weeks; it later passed 50 million and then 100 million downloads, a rare feat for an app made by one person.

Smith is also an influential voice in the indie Apple community. He hosted the short podcast Developing Perspective about becoming an indie developer, then co-hosted Under the Radar with Marco Arment for a decade, and in 2026 revived Developing Perspective to explore how AI tools are changing what it means to make apps. He writes about craftsmanship and sustainable indie development on his blog.