Default "Open With" in iPhone Mail

I made my iphone app so it can be associated with PDF fi开发者_如何学Cles. somehow it seems to me that Evernote set it self to some kind of a PDF default because in PDF attachments i see their icon and they show as the default option.

is there a way to declere my app as a default rather then just associate it with the file type ?

Thanks

You can set your app as Owner of a file type instead of Alternate to try and see if you are set to default, but whatever is the last user choice when opening the file type, it will be set as default instead of your app.