I use Seller Tools to tweet my Etsy products. I love the automated feature meaning I just had to set it up once and leave it to tweet automatically for me. I liked that I could choose my main product photo for my tweets and the frequency of tweets. I have noticed increased views on my Etsy shop directly from the Seller Tools auto tweets!
What is the most useful for me is that I can schedule posts for my shop throughout the day. Even if I was sitting at my computer all day long, I wouldn't be able to keep posting for different time zones worldwide.