You have to install apk’s while there is no playstore running on it.
Did you already follow the instructions on Blakadder.com to be able to install other applications?
Don’t know what you are looking for. The smart dash app is for example good to use with the nspanel pro. There is a topic for this software on the community forum. You need to install the APK one time, updates are running directly via the app without the need of the playstore.