To install a mobile application on an iOS device (iPad, iPhone, iPod), the file must be authorised and come from a known source. What exactly does it mean? You can install the application in two ways. One way is to download the application from the official AppStore mobile store directly to your device. A unique AppleId is required to use AppStore. If you do not have one, you must obtain it on Apple’s website.
The other way is to use a ready-made .ipa installation file. As described above, it must be authorised, which means that during compiling, a unique ID (UDiD) of the device on which the application will be installed must be added to it. How to read the UDiD from an iOS device? Find the answer in this article. Once you have the properly prepared (compiled) .ipa file, connect your device to the computer and run iTunes, which is necessary for the installation. iTunes will detect the connected device. Then double click on the .ipa file – the application will appear in iTunes. Click on Synchronise, and then Apply. Once the synchronisation is completed, the application is installed and ready to use.