I'm using Mixpad on my iPad pro. Everything seems to work fine and when I export mix as an .mp3, it goes through the process but I don't know where to find the file to send it somewhere from my iPad. Would ideally like to save the mixed .mp3 into my Drop Box folder. Where is the file? It shows in the projects but how do I do something with the final mixed .mp3 which is the whole point for me? BTW, I purchased the feature "All output formats." Thank you.