I completely agree with Rene on this topic and its better late than never that we get a file picker for iOS. And I think the timing is also right as iOS has matured enough and its users are comfortable enough with it, for a file picker. I have for long wanted to replace my Dropbox folder with Apple's iCloud Drive. But unfortunately the biggest use case for me for Dropbox is an online storage drive that replaces the traditional flash drive that I have to carry around. With iCloud drive I was finally hopeful of using an Apple's service instead of a third party one (as if I have to trust one company with my sensitive files/information, it would always be Apple for me) in this regard, but as it stands now, iCloud Drive cannot replace Dropbox for me. So I am hoping for this feature on iOS as soon as possible with fingers crossed!