We take a quick look at the Tweet Old Post WordPress plugin from ThemeIsle There is a very useful free version that goes through your old blog articles and retweets out the headlines and links again. You pick the categories to choose from and the interval and it does the rest. If you want to tweet featured images as well or tweet posts to more than one twitter account they offer a very inexpensive plugin add on as well that only costs $9.99. Check out the video and maybe it will help you decide if this is a good tool to add to your tool belt!
source