What are your favorite travel-related apps, app features, or websites?

Favorite, most-used, or just cool.

Please also mention how you use them (if in a special way).

Here's my list:

• Google Maps offline maps (saves ton of data)
• Google Maps "want to go" feature (for bookmarking places)
• Google Translate + the offline language pack (another life saver in places with no service)
• WhatsApp or Instagram of course (for communicating with friends/family)
• Flighty (the flight tracker app; I use the free version and love it)
• Airbnb experiences (for very popular experiences with lots of reviews, I’ll just use Airbnb for discovery and book them directly outside of Airbnb)
• AI (for discovering places and foods, I’d like Gemini over ChatGPT or Claude because it has pics and integrates with Google Maps. Mindtrip.ai is also cool but has a lot to improve.)
• YouTube Premium (for offline downloads on the flight)

Technically not just an app but a couple of honorary mentions:

• eSim apps (Simly, Airalo, and Holafly; my favorite is Holafly because I can't be bothered with rationing data. A great comparison on YouTube.)
• Wise card + app (simple way for FX and spend).