Hey Forum, i would like to do remote updates on screenly ose on the raspberry pi but at the spot there is no wifi and no network access allowed.
Anybody an idea? Thank you very much.
Andreas 
I use my cell phone’s hotspot to connect to the internet for updates.
Since I usually move mine from one location to another, having the network settings not change is helpful.
Sadly, the only way I got this to work is to have it near my main computer so that I can log into Screenly and connect it to my hotspot. Since my hotspot does not alter it’s DHCP leases often, the IP of the Raspberry Pi doesn’t change between connections or boots and allows me to log in using a second portable device.
The short is that I have the hotspot on one device and use a different device to connect and control Screenly.
The only way to do this is as @jonply points out using some kind of hotspot or similar. Using a cellular hotspot is the most common solution for this in an environment where you are unable to utilize local network connectivity.
Have you tried an SSH program for the smartphone? I use JuiceSSH and it is amazing when I need to remote into the Pi without having an actual computer…