Flat is in. There’s no doubt about it, and no style has taken the design world by storm quite like flat design. Whether you’re creating brochures, posters, websites or apps, you probably don’t want to have to continually create custom icons. Fortunately, many talented icon designers are willing to share their flat icon sets for free or minimal cost. Start adding to your stable of design assets with the following 30 flat icon sets, which represent a total of more than 2,000 icons.