Be careful, there are no full terms&conditions published anywhere. Because it's Miles&More specific, I suspect you must register your account to earn miles rather than points before installing the app or doing anything else. Also, since there is no explicit registration, I have no idea how IHG intends to track this promo.
Here's the M&M announcement:
https://www.miles-and-more.com/onlin...mc_id=MRSSP000 - thanks to
gojko88 for sending the link.