Etsy app on my iPhone. The "cha-ching" sound when something sells gives me a thrill. It's also been nice to instantly respond to conversations. I don't know what your experience has been, but I've found that most people that contact me tend to ask a question and then never respond to the answer I send.
They'll ask about a custom order, adding a necklace to a pendant, etc. For custom items, I tell them that they'll need to pay in advance and then I never hear from them again. The majority of the convos I get on Etsy are asking about items I sold in the past. Since we tend to make things as the mood hits us, much of what we make is pretty one-of-a-kind. We often don't have the same materials available to be able to make more of the same item.
Today was a much more positive experience. Someone who had been searching the Internet for a specific items was happy to find what she was looking for in my shop. The color wasn't exactly what she wanted so she sent me a message. After some conversation back and forth via the Etsy app on my phone, I knew that I had what she wanted even though I didn't have it listed in our shop. I quickly took some photos and was able to list it through the app. Within minutes, she bought the item and was very happy.
Have you tried adding a new listing through the Etsy app?