Check out our blog. We reveal much of our methodology there. Also check out flagged reviews -- each will have some explanatory text.
We exclude reviews that might be untrustworthy from the star rating calculation. So an app that has 4 stars in the App Store might have, say, 2 stars on AppRecs if many of the positive reviews aren't deemed trustworthy. Additionally, we only use reviews in the calculation, so an app whose reviews are all trustworthy could still have a different rating on AppRecs since the App Store's rating for that app includes ratings from users who have just left star ratings with no review text.
AppRecs may not have all reviews for a given app, and the review data it has may not be up-to-date. This is partly due to the fact that it must pull this data from Apple, which itself doesn't guarantee the quality or completeness of the data. Most notably, the API that provides customer reviews is limited to the several hundred most recent reviews for a given app. That said, we strive to provide a high-quality experience, so please give us a shout if you notice anything that seems more than a day or two old.
The site is totally free to use, and there is no advertising. We only earn income via Apple's affiliate program. It costs a lot to run the computational resources and the website, and we hope some day to at least break even on expenditures vs. revenue.
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