The 'Install Profile' action will download and install a BuildStore-specific Configuration Profile to your mobile device. 

What does "Configuration Profile" stand for? 

All applications we provide are installed based on official Apple app distribution technology, and device UDID is a required property for this process. 

Configuration Profile allows BuildStore to get your unique device UDID to enable an app installation process and connect your Subscription with the device. We also need to recognize your device to make initial arrangements on our site to set your account up and running. We use IMEI, UDID, Product type (iPhone, iPad, etc.), and version. 

Profile installation makes no changes in your initial system, and it doesn't get access to your private info stored on the device. 

If you're curious how to install a profile, here's the official Apple guide: