#datafree apps are currently only available on Android phones (e.g. Samsung, Huawei)
Most smartphones such as Samsung, Huawei and many more are Android phones. An Android app file is called an APK. iPhones are not Android phones and use different types of apps.
To install the app on your phone #datafree tap the APK link for the app you want. Depending on which cell phone you have you either be asked if you want to install the app, in which case tap install. Or you may be asked to change your security settings to allow installation of apps from sources other than Play Store. Slide the switch to on and then install the app. You should slide it back to off when the app is installed. One some phones the slider moves back automatically once the app is installed.
Go to Settings >> Unknown Sources