TL;DR: For most developers, accelerometers are tools for productivity or performance. Tonino Catapano saw something else: a chance to make MacBooks groan when you slap them. The Amsterdam-based developer is behind SlapMac, a novelty macOS app that turns light taps or full-on smacks on a MacBook into a range of sound effects, from dramatic moans to digital punches and exaggerated groans. The app relies on the laptop's motion sensors to detect impact, scaling the volume based on how hard the device is hit.
The idea came from social media. Catapano posted a short Instagram clip of himself slapping his MacBook, complete with sound effects and a mock groan. When the clip unexpectedly went viral, he decided to turn the gag into an app.
"I built it. Swift app, landing page, licensing – everything. 48 hours from zero to release. Listed it for $5 and the sales started coming in and haven't stopped!" Catapano noted on Reddit.
Within three days of launch, SlapMac had reportedly drawn more than 7,000 installations and $5,000 in revenue. The app's early success appears to have encouraged Catapano to expand its feature set. In addition to the core "slap response," users can choose among nine collections containing roughly 160 sounds.
Most of the variety sits squarely in the comedic or deliberately absurd categories – including what the developer describes as a "sexual moans" set. The program can also simulate cracks on the screen for added slapstick realism.
New features have already rolled out. A recent update introduced USB Moaner, a companion option that makes the MacBook "moan" each time something is plugged into its USB port. Catapano has also added a break timer, adjustable sensitivity levels, and a built-in counter that tracks how many times a user has hit their device – a curious metric that turns slap frequency into a sort of gamified stat.
What began as a throwaway joke has quickly taken on a life of its own, gaining traction across forums and social platforms. SlapMac sits in that familiar gray area between parody and product, a piece of software that doesn't solve a real problem so much as it playfully exposes how easily Apple's hardware sensors can be repurposed in unexpected ways.
For now, Catapano seems happy to keep refining his creation. With the tagline "slap responsibly" making the rounds online, SlapMac is a great example of internet humor at its weirdest.