Apps that still work when the data does not

The setup is ten minutes on hotel wifi, and it is the difference between an inconvenience and a bad afternoon.

Connectivity abroad fails in predictable ways: the eSIM does not activate, roaming is off, airport wifi wants an SMS you cannot receive, or you are simply somewhere with no signal. The fix is not better connectivity. It is a handful of apps that never needed it.

The five worth having

• Maps, downloaded. Both Google Maps and Apple Maps let you save a region for offline use, and dedicated hiking apps do it better for trails. Download the city before you fly. GPS itself works without data — it is the map that needs downloading.
• Translation, downloaded. Google Translate and Apple Translate both offer offline language packs, including camera translation for menus and signs. The packs are per-language and must be downloaded deliberately.
• A currency converter that stores rates. Since iOS 18 the iPhone Calculator does this for free. A dedicated app is worth it if you convert constantly or one-handed. Either way, test it in airplane mode before you go.
• Your documents, saved offline. Boarding passes in the wallet app, accommodation addresses and booking references screenshotted. A booking confirmation you cannot open is the same as not having one.
• Transit maps. A screenshot of the metro map is unglamorous and never fails.

Also worth doing before you fly

1. Screenshot your accommodation address in the local language and script.
2. Save an offline map that covers the airport and the route into town.
3. Download the language pack, not just the app.
4. Note your first-day cash needs and the local conversion rule.
5. Charge everything, and carry a battery pack. Every offline app in the world is useless at 0%.