Test flight
I am not a developer. Why is test flight on my phone?
iPhone SE (2nd generation)
Question marked as
TestFlight is used by users testing apps for developers, as well.
Why is TestFlight loaded on any particular iPhone?
Usually because you (or someone with device access or Apple ID access) loaded the app.
Are you sharing an Apple ID?
If so, devices can be set to automatically download apps loaded on other devices sharing the Apple ID.
Sharing an Apple ID is not recommended, and causes all sorts of things to be shared past app acquisitions.