The idea was that not every part of the day is perfect to tweet, and also that sending to many tweets one after the other might put off your followers. Such things don't sound personal use, but if you are tweeting on your companies behalf then it's a different story.
Buffer has grown a lot since then and lets you manage your Twitter, Facebook and Linked in accounts, all at the same time. But the best part is that Buffer offers apps for iOS, Android, browser extensions and is even integrated into many other services across the web, like: Pocket, Feedly, Instapaper, and most recent Followerwonk.
