For the Nuu F4L try *#666# to unlock APK installation. It works for the Aspera F42 which is essentially the same phone in Australia.

a month later

Does anyone know why ##228378 isn't working on my LG classic flip L125DL?

    pprobely disabled by filter

    ahashemlover probly blocked nothing there is to do unless you remove your filter

      11 days later

      Chaver

      Chaver just go to settings, About phone, click the build number seven times

          19 days later

          TheName5623 Go to, settings, system, about phone, software info. click on build number 7 times. This will unlock developer options.
          to access developer options, go back to system.

            Kyocera Cadence is not have a secret codes like ##228378

            a month later

            chaimzalman
            I'm still looking for it if you figure it out please let me know

              a month later

              what are the codes for the jitterbug lively flip2 which is some sort of alcatel go flip?

              23 days later
              6 days later

              does anyone know how to unlock the submenu in developer options for Kyocera Dura XV and Cadence that allows options for app permissions and apps from unknown sources. The menu is there, but not generally accessible. (incidentally, those options are accessible in the Kyocera Dura Extreme).

                13 days later