Since 2019 it has become apparent that many people have not been properly prepared for Expo.
This is what you need to do:
For the latest updates for the most recent phones, go to: dontkillmyapp.com
Phones assume that you are walking along streets, or running along tracks or cycling. They are very bad at making the right guesses for the Totes Gebirge plateau.
Do not select the "high accuracy" location setting on your phone. Mostly this will snap your position to the nearest cafe or bierstube: by default it will use the nearest WiFi it can find and assume that you are there, and will ignore the perfectly reasonable GPS position it has recorded directly.
This is all explained by Google here.
On the plateau, this "high accuracy" mode will simply give you the wrong position if it can't get a decent GPS fix. There is poor cell tower reception too, so trying to use that for location is just as bad.
What you want is GPS and only GPS (more precisely GNSS: which includes GPS, Glosnas, Beidou, Galileo etc.).
If you do not have a good GPS fix, you want to know that, not be given some confabulated guesstimate by whatever some programmer for Apple or Android thought your might want.
When you share photos on your phone to the Expo photo sharing site, by default, the location of those photos will be stripped out. So all those lovely pics of intriguing cave entrances you snapped on your walks are now utterly useless.
So, before expo, perhaps while sitting in a traffic jam around Munich or on the train from Bad Ischl, take a moment to photograph your travel companions in an embarassing pose and fix the this:
Even if you have no intention of using your location or recording a track, the camera in your phone will record locations of your photos which are extremely useful to future expeditions - for reasons which only become apparent when you yourself try to work out what someione did 10 years previously.
Your camera will use the same locaiton settings as the rest of your phone, but sometimes with a bit of a delay. We have lots of examples of geo-located photos where the recorded location is alctually the location of the previous photo because someone has taken a quick photo but the phone hasn't had time after waking up to get a location, so it uses the previous one! And doesn't tell you!!
So when taking a photo of an entrance, always take one photo; delete it, and take another. This will give your phone a chance to get synchronised properly.
ALSO: always take 3 photos of any entrance, the obvious one about 10m away, a scene-setting one from 20 or 30m away, but also a really close one of 3 to 5m away, so that we can see if rocks have moved around the entrance and also for a much better identification in future. If there is a tag, always take a close-up photograph of it so that the letters are readable.
So that we can spend less time looking for the body in horrible conditions...
[someone write this is a less frightening way, please?]
If recording a track, you do not want your phone to decide to go into "energy-saving mode" (the default if you are not actively interacting with your mapping app, such as OSMand) as it will drop location points and your recorded track wil now gaily bound over impenetrable chasms, rendering it rather useless for finding your way home in thick cloud.
Unless you have already done a couple of days with your phone set into "continuous GPS mode", you have no idea how long your battery will last. So if you haven't already practiced this on a fell in the UK, you need to bring a phone backup battery with you on expo.
You can buy phone battery backups in Austria, but they are a bit epxensive, and hard to find in Bad Aussee (try the post office phone shop, or the deviously hidden electronics repair shop in central Bad Aussee).
detailed instructions depend on the type of phone and the version of Android - someone fix this ?!