I like the concept of the document picker, being able to have one copy of a file and open it from different apps. However, not many apps have implemented this functionality, or only partly. And I encounter bugs when using it with apps which support it (mostly apps freeze and have to be killed). For example I can open, edit and save a document in PDF Expert from Pages. But when I go to PDF Expert after that, the app freezes. I have to kill both Pages and PDF Expert to get things working again. So I don't know if this is a bug in PDF Expert, Pages or iOS itself. How is you experience with document picker?