If you are an IOS user then you must know that you cant install the applications on your iPhone which are not present in the App Store, that's why there is a way to download and install third-party applications on your IOS devices that are known as Iohelper. On this Website, you can find and download that app that is not available in the App store.
Read more: https://infomafia.net/iohelper-co-ios-users-way-out-for-third-party-applications/