I like the Sales Events Tool! Especially how it put the sale price at the top of the listing and how it calculates the percentages and shows the "sale" and "was" prices!
Not only does it help and save my time on a daily bases but, the automated portion is awesome! You set it up, which takes no time at all and that's it... Seller Tools does the rest forever! It's very user friendly, which is a PLUS! Customer service is fabulous, they answer you in a timely manner and actually help you! Can't say enough about this app, so glad I found it!