LIDO App
Select an airport from the drop down menu on the left.
You should see airport info including longest runway, elevation, co-ordinates.
To the right of that info is a white box headed "last update:never"
Below that is a "download" button - click on that.
Repeat for each airport you want.
In the drop-down menu a green bar will appear at the left of the airport name.
As each update expires, the bar changes to red, click on the download button again to refresh and update.
There will also be a "remove button" if you want to free up storage space and don't need that airport info for the moment.