how do you set adobe as the default reader on a apple ipad mini. It keeps asking what to open pdfs with and its a pain.
When you open a PDF attachment from your email then it opens up in Apple's built in PDF viewer.
In order to open it in Acrobat Reader you have to Tap Share icon>Then choose Copy to Acrobat.
For detailed information please refer to the help document for the same- Acrobat Reader Help for iOS: Opening PDFs in Acrobat Reader
Unfortunately, Apple does not provide a mechanism for iOS users to set a default app for a given file type (examples: .pdf, .docx) on iPhone/iPad.
You just need to continue using "Open in" or "Copy to" to open PDF documents in Acrobat Reader on iOS.
Sorry for the inconvenience.