Over the past 2 weeks, a good chunk of iOS apps was hit by a major drop in discoverability and, as a result, downloads. Last Thursday, our Head of ASO Ilia Kukharev found out the reason for that: the App Store stopped indexing subtitles with 30 symbols properly. The last word of a 30-symbol subtitle won’t be “found” by the App Store, therefore, your app is not going to rank and get traffic for it.
Funny enough, apps with subtitles of 29 symbols were not affected by the plague and didn’t lose any positions in the store. This bug seems to have affected lots of developers and publishers and still hasn’t been fixed.
Subtitle helps app owners use more keywords and rank higher in search, and has a stronger impact on app ranking than the keywords field (app title has the strongest one though).
Russ Shannan, the creator of Happy Scale app, faced the same issue and after cutting subtitle of his app by 1 character got back to the App Store search together with gaining his downloads.