Firefox / uBlock Origin only showing camera / image apps when clicking on a file upload button I'm looking to import my uBlock Origin settings from my desktop PC, which is in a text file, to uBlock Origin in Firefox for Android. 

The issue is: When I click on the 'Restore from file...' button on uBlock Origin in Firefox Android, I only get prompted to choose between camera / image apps:



In a Windows PC, clicking on that button will open up an Explorer window allowing you to select a text file to import. I can't import a text file with any of the above apps  shown. Is there an app I should install to allow this? How should I configure it?

Details: I have Google Drive and ES File Explorer installed. This is on Android 4.4.2, Firefox for Android 44.0, uBlock Origin 1.5.5.
As confirmed by OP this app resolved the problem App Picker Classic. From app description


  If you have app choices that are currently hidden - maybe you chose "Always" by accident once, but you'd like to be able to reinstate the app and choose each time - then reset these by clearing the defaults in the application manager of your phone/tablet.


In addition, this app permits working with some app intents and resolves common URLs. One needs to install the app, reset defaults and enable required app.

Note

Despite the app being not updated for last two years, it even works with Marshmallow, as can be seen from @Arlinds answer here - which was a surprise to me, and the reason for remembering it !