Salestio — Amazon, eBay, Etsy

The app is probably good if you start everything from scratch. It doesn't handle migrating existing listings on ebay very well. Therefore, I stop using it because of that and it caused so many unhappy customers when they order out of stock products because the listings are not updated. The concept of selling lists might leave you with duplicate listings of a same product. It's hard to know which listing is from which selling list and that makes the manual problem solving process even more difficult. Nevertheless, support is good and timely.