I enjoy sharing things on Twitter and Facebook, but I'm totally inconsistent. One day I'll tweet a few times, then nothing for three days, then a mad burst of sharing and retweeting. If you're like me, Buffer is your new favorite app. It schedules your tweets and Facebook posts for you, creating a consistent social media presence. (It also supports App.net and LinkedIn, and is available on iOS and Android.) We talked to Buffer's co-founder Joel Gascoigne about the inspiration for the app, his biggest challenges, and what it feels like to celebrate 1 million users.