I purchased (2 codes) 6 weeks ago. Added my courses, meditations and ebooks and I made over $2,000 dollars so far. People love the app (included with the appsumo deal) and is so easy to navigate and communicate with your users (similar to a push-notification feature). And the fact that you could listen to the audio file on off-line mode is a killer feature. Many people dont have lighting speed internet and many of my students purchased access to the audio file programs that I offered because of the offline option and their poor internet. If you sell courses, music, eBooks or just want to have a premium based podcast where you could charge money for it, this is your tool.
If you dont buy now you are going to regret later. Big time!!!
Thanks Appsumo team and Soundwise developer for bringing this great deal.