in-app pop-up box offering to review the app

A pop-box asking people to review and rate the app on iTunes. As it is the norm in many other apps.
This might help drive app reviews numbers.

I know there are a third-party SDKs of this feature out there so implantation should not be hard.

https://blog.kissmetrics.com/wp-content/uploads/2014/04/4-rate-our-app.png