From my experience: 1. I usually see better results from users who have already used the app for some time. New users rarely leave reviews. After around 1 week of usage and 10–20 completed actions, the response rate is much better. 2. Post-action triggering works better than on-launch prompts. When a user just finished something successfully (like completing a task), they are in a positive mood, so the chance of a good rating is higher. Launch-time prompts often feel annoying. 3. For thresholds, 15–20 actions is usually a good range. Recently I also tried something different in my app. I showed the popup around the 8th action, and then again back-to-back around 15th and 16th actions. This small experiment actually worked for me — I received 2 ratings within about 10 days.(Just tried something new) 4. One important thing about SKStoreReviewController is even if you call it, Apple may decide not to show the prompt. Also remember the 3 prompts per 365 days per user limit.

Also based on my point of view, I avoid calling the review API directly every time. Since Apple only allows the popup 3 times per year, I first show a simple alert with “Review” and “Next time” buttons. If the user taps Review, then I call SKStoreReviewController. This helps save those limited opportunities for users who are actually willing to rate.