Thanks gynta for your clip !

after frech download of "germany_south.osm.db" i see the hamburger button top right and can select offline address search

my test address:
Stuttgart Flughafen Flughafenstraße
-
Stuttgart street
Flughafennext i take a look on map and see names of towns around the airport to search for
-
Echterdingen-
Plieningen-
Filderstadt street
Flughafenstraße- Leinfelden >result
Leinfelden-Echterdingen street
Flughafenstraße 
for now a foreign visitor didn´t find the Airport of Stuttgart

surprisingly searching with same DB using "POI search" i get results for "Stuttgart Flughafen" or "Flughafen"