Apptentive Offering ratings prompts and management, in-app polling and messaging and a growing list of features, Apptentive has built their business on helping publishers maintain a happy and engaged user base. Asking Point Similar features set to Apptentive, different pricing tiers and a focus on automation. Or check out an example of a custom implementation shared in a case study from the news app Circa: The Right Way to Ask Users to Review Your App
If you are thinking that there must be a more user-friendly way to prompt for ratings and reviews - allow me to throw some water on the fire.
"We appreciate you taking the time to rating and review our app - here are some smurfberries". Not allowed and your app will be rejected. The thinking is that these offers incentivize 5 star ratings (even though the smurfberries are rewarded regardless of rating).
The small task website fiverr used to be littered with offers for app reviews. Similar to buying Facebook "likes" or Twitter followers, you could just pay a service to generate a huge # of ratings and reviews for your app. Both Google and Apple are not only very aware of this issue but often take significant steps to deter this behavior. The purchased reviews will be discovered and removed, and your app will likely be penalized or even removed from the app store. If you decide acquiring mobile app reviews and ratings is an important part of your app marketing, avoiding the above restrictions and using examples in this post will help you get started.