Awful
Response from developer
There is now an update which fixes this :)

This app helps Pokémon trainers find opponents and calculate effective moves using a comprehensive offline database. It's designed to exploit type advantages and avoid ineffective attacks, making it ideal for challenging gym leaders and the Elite Four.
5.0.0
April 24, 2023
New version to comply with Apple's 3 year update minimum
There is now an update which fixes this :)
Battle Types is a paid app that helps Pokémon trainers find opponents and calculate the most effective moves by exploiting type advantages. All data is stored offline within the app.
No, Battle Types is ad-free. It is a paid application with no advertisements present.
Battle Types is available for iPhone and iPod devices.
The app was last updated on April 24, 2023, with version 5.0.0. Update frequency can vary based on developer plans.
Battle Types has an age rating of 4+, making it suitable for younger players interested in Pokémon strategy.
Yes, all data for Battle Types is stored offline within the app, allowing you to use it without an internet connection.
Battle Types is a paid app priced at $0.99.
Battle Types is especially useful against gym leaders and the Elite Four by helping you find opponents and calculate the most effective moves to exploit type advantages.