Downloading error on Fire kirin app

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Why are you telling us?

This is a user to user support forum.

The developer is not here and you aren't asking a tech support question.

Apk files are for Android phones, they won't run on the iOS platform. Some how its been compiled to run on iOS, good luck with that.

Downloading it from anywhere else but the App Store is a bad idea, there is no telling what malicious code could be in there. You're on your own from here, no one is going to help you check the the issue.

Even so, as others have told you, this needs to be fixed by the developer, it is not up to Apple to fix 3rd party buggy programs.

That app is not in the app store, so the only way to install it is to hack your phone by installing an unauthorized certificate that can put your phone at risk of infections with malware, and the app itself may contain spyware or malware. It is easy to have an app listed in the app store, as long as it adheres to Apple’s privacy and security policies. That’s why there are over a million apps in the app store.

The logical conclusion is that any app that is NOT in the app store violates Apple’s privacy or security policies, because if it didn’t it would be in the app store.