Thanks. As I recall, when I tried to sideload the browser, Puffin, I noticed that the version that worked on my Jolla Tablet was extracted from a phone that had either KitKat or Marshmellow firmware (can't remember which right now). The version I tried that came from phone with Oreo did not work . Same thing happened when I tried to sideload Firefox. This is not the case with all apps. But seemed consistent with browsers which might be understandable based on security issues that might be addressed with more recent SDK. Or could be some other reason...