Free trial for App Store apps and games are coming
New App Store guidelines are finally going to allow developers to offer free iOS app trials for all titles, not just those based on subscriptions. Yes, this means you’re finally going to be able to try apps and games before you buy.
According to section 3.1.1 of the new guidelines, to enable trials, developers must create a free in-app purchase with a definite expiration date.
全文及來源：
http://www.idownloadblog.com/2018/06/06/free-ios-app-trials/
Developer
App Store Review Guidelines：
https://developer.apple.com/app-store/review/guidelines/
若開放試用APP，就能讓減少使用者被退款搞瘋的麻煩，
但要到普及的程度，還需要很長的時間才有可能，
減少買到不適合的APP、不小心就訂閱的機率能讓使用者輕鬆許多。