I don't think you will be able to download directly to iOS unless you can find a used Dive Computer Buddy, you will have to use a Windows or Mac computer.
That's the conclusion I'm coming to as well. I don't particularly like either the OC-1 that I use or the ProPlus3 on my wife (my buddy's) kit but they do work; it's the two button UI that really annoys me. I guess I'll use the Windows download from Dive Log 6.0 (it syncs with Dive Log on our iPhone's) until I shell out for new stuff but it won't be Oceanic/Huish. The remaindered VTX's ($400) looked attractive but same UI; fool me once.