Don't let people tell you your ideas won't work. If you're passionate about an idea that's stuck in your head, find a way to build it so you can prove to yourself that it doesn't work.

What we're starting to see is that the best apps tend to be the simplest, the easiest to use and the fastest to use.

If there's something you want to build, but the tech isn't there yet, just find the closest possible way to make it happen.

Building a product is easy. But building the company that builds the product is hard.

Do what you love and the rest will come.

I keep a notebook in my pocket, and I write down all the stuff we could ever do with Foursquare.

Stop sketching and start building.