How do add/remove an app from the Open With app list on Android Marshmallow?

[AC Question]

When my device offers to open a file type, it gives me an Open with app list.
However, the apps here are of no use and I need to remove them and add appropriate apps instead.

 

[AlphaTango414]

You can't. You can set it to use one program for when you open that particular file type.

You can't add to the list, every app that is coded to support the file type is shown automatically. If an app doesn't show up it doesn't support it / is not coded to open that file type.

Can you give an example of file type and the app you are wanting to use??

 

[Enigma_X]

Example
I have a .docx file attached to an email.
I have Freader docx setup to view this file type.
However, when I 'click' the file attachment icon, the Open with app list shows 'IT jobs' and 'Printer Share' and no other options.

 

[Enigma_X]

Example
I have a .docx file attached to an email.
I have Freader docx setup to view this file type.
However, when I 'click' the file attachment icon, the Open with app list shows 'IT jobs' and 'Printer Share' and no other options.