Ratings: the number that ranks you
New ratings are the strongest behavioural signal, and they only arrive when you ask at the right moment.
Apple lists ratings and reviews among the things that move rank, and practitioners who track thousands of apps put the rate of new ratings first among them. An average under about 4.3 also costs downloads directly: people read the stars before the subtitle.
Ratings do not arrive on their own. Ask with Apple's own prompt, after a moment the app has just delivered something (a streak reached, an export done, a third session), never at first launch. The prompt is rate-limited by Apple to a few times a year per device, so the moment matters more than the frequency.
Read your written reviews the way you read a competitor's: the complaint that repeats is the next release, the praise that repeats belongs in the subtitle. A listing that promises what the reviews praise converts, and a release that fixes what they complain about raises the average.