Brian Mueller

Brian Mueller is an American independent app developer best known as the creator of CARROT Weather, the iPhone, Apple Watch and Mac weather app voiced by a sarcastic, homicidal AI. He runs Grailr LLC, a one-man studio in the suburbs of Philadelphia, and writes, designs, codes and markets every CARROT app himself.

Mueller was on track for a career as a Hollywood screenwriter before choosing to settle in Philadelphia and take a conventional job. With no coding experience, he bought a book on iOS programming intending to learn just enough to hire a developer, found he picked it up quickly, and built the apps himself instead. His screenwriting background shows in CARROT's personality: the character began as a snooty cartoon dog and became a scheming AI that insults its users, the meatbags.

The first app, CARROT To-Do, arrived in 2013 and got 27 downloads on its first day. A talking alarm clock, a fitness app and a calorie counter followed, and by April 2015 the CARROT apps had passed one million combined downloads. CARROT Weather launched in 2015 and became the franchise's breakout: it pairs real forecasts from multiple data sources with thousands of lines of dialogue, secret locations and achievements.

The app has since collected Apple's top honours. It won a 2021 Apple Design Award in the Interaction category and Apple's 2021 Apple Watch App of the Year, and it has been an App Store Editors' Choice. In January 2021 CARROT Weather 5 moved to a free download with Premium and Premium Ultra subscriptions, and version 6.0 brought a full redesign. Today it runs on iPhone, iPad, Apple Watch, Mac and Apple Vision Pro.

In October 2025 Mueller joined John Gruber on The Talk Show to mark CARROT Weather's tenth anniversary. He still develops the app alone, which makes CARROT one of the clearest examples of a solo developer competing with venture-funded weather apps on design, personality and Apple-platform depth.