FlipAPenny is fully localized in 5 languages: English, French, German, Spanish, and Italian. Every item name, NPC dialogue, trade description, and menu is translated.
The quickest way is in the game: open Settings → Language, pick one of the 5 languages, then reopen the app. You can also use your device's Settings app:
Open Settings on your iPhone or iPad
Scroll down and tap Apps
Find and tap FlipAPenny
Tap Language and select your preferred language
When you change it from your device's Settings, the app restarts in the new language straight away.