Spantop

Aditya Dewaskar built Spantop because he got tired of pretending his laptop screen was enough. It's an app that turns any Mac into a real second monitor—no cables, no hardware, just download and extend your display instantly. For developers, designers, and everyone else who's ever maximised windows to fit them on a 13-inch screen, this is the cheat code you've been waiting for.

External monitors cost hundreds of dollars. Spantop costs nothing. It's free on the Mac App Store with optional in-app purchases, which means it's already in the hands of anyone who's ever wanted more screen real estate without spending big bucks. Aditya appears to be flying solo on this one—an indie hacker building tools he needed and hoping others needed them too. That kind of simplicity rarely lasts, but when it works, it works. If you've ever stared at your cramped laptop display and dreamed of a second screen, Spantop just handed you one for free.