Sean Rad was frustrated with traditional online dating. He and his co-founder created a simple, fun game-like app that was low-commitment and introduced swiping.
Tinder was created.

Kevin Systrom loved photography and wanted a simple app to edit and share photos with his friends. He started by building a simple tool for his own use and focused on ease of use and aesthetics.
Instagram was created.

Brian Chesky and Joe Gebbia needed a way to make extra money because they couldn't afford their SF apartment rent. They decided to rent out air mattresses to attendees of a local conference.
Airbnb was created.

Drew Houston always forgot carrying his USB drive. He created a tool for himself to sync files without needed any external storage.
Dropbox was created.

Jan Koum didn't want to pay for international texting.
WhatsApp was created.

Steward Butterfield team was building a video game (Tiny Speck) and needed a better tool for internal communication.
Slack was created.

Steve Chen (and two more) wanted an easy way to share videos with their friends after a dinner party but couldn't find a simple platform to do so.
YouTube was created.

This is one of my go-to podcasts: How I built this by NPR to learn about these stories.

When you design for one person, you can go deep on solving absolutely real problems rather than diluting your design to please everyone.

Pick one person—whether it’s a friend, family member, or yourself—and design a solution to a specific problem they face. Ignore the broader market for now. In doing so, you may just discover something that appeals to many.

“Start by solving problems that you know people have. Often that means starting by solving your own.” — Paul Graham, Y Combinator