“Search for terms, keywords and phrases around what your app does by typing in the first few characters into search — you'll see a list come up. By looking at those lists I was able to determine what are the most high impact keywords people are searching for.”

Mine App Store autocomplete for the long-tail keywords users actually type

Free ASO keyword discovery: type the first few characters of a query into App Store search and read the autocomplete dropdown. Most users tap entry 1 or 2, so those suggestions are the actual high-intent queries. Target the specific long-tail entries — lower volume but easy top-5 ranking, which then lifts you for broader terms.