iOS 10.3+ and Android 5.0+ have the ability for the user to review your app from within the app itself, this command will tell iOS or Android to start this process. Note that it is not guaranteed to display anything when you call this command, and it should not be called in response to a button press or other user interaction. You should call it when there is a lull in the app such as the end of a level. If you want to start the review process in response to a user action, such as a button press, then you should use the OpenBrowser command to open the AppStore.
RequestAppReview()