Hello there,

Here you have an article where Google announces that Google Fit application is also available on iOS, in order to expand its reach. 

Have any of you already used it?

Find below two good links with reviews for the Google Fit health app on iOS
https://mashable.com/article/google-fit-health-ios-apple/?europe=true&utm_campaign=hp-h-18&utm_source=internal&utm_medium=onsite
https://www.engadget.com/2019/04/24/google-fit-for-ios/