Otter is excellent for speech-to-text transcription - amazing if, like me, you're the kind of person who'd like to use a dictaphone but can't be arsed to listen back through your recordings.
Google Translate really comes into its own when you point the camera at text...
Garmin Connect and Strava, obviously.
Tesco Clubcard because you need it to get Clubcard Plus benefits (yes, I've sold my soul to the Church of Tesco).
Night Sky is a neat stargazing app.