Is the lunar calendar (Vietnam) app market saturated? What the App Store US data says

Chart read on 30 of the last 30 days.

Only the top-grossing chart counts. Top-paid charts are left out: paid-app sales are thin enough that almost any paid app reaches one. Each category chart lists the 100 highest-earning apps in that category on this store, so the bar is far higher in Games than in Medical.

73 of 74 apps holding a top-10 position have rating readings spanning 14+ days.

App Store rating counts are kept per country, so these are App Store US ratings only. Google Play counts are worldwide. Compare apps within one store, never across the two. A rate is the rise in rating count over the days observed in the last 30 days; a drop of more than half is read as a counter reset and earlier readings are discarded.

Difficulty is the cost of reaching the top, 0–100. "Apps targeting it" counts top-10 apps carrying every word of the keyword in their name or subtitle.

Mixes the slice of reviews the store chooses to show, which skews positive, with each app's latest reviews — so the shares show which problems dominate, not how many users hit them.

Each 1–2★ complaint was assigned one theme by an AI model. A second AI model re-read 100 random labels in September 2026: about 7 in 10 matched its own pick and 9 in 10 were a reasonable reading. Read the order of the leading themes, not exact shares. Classified on 2026-10-09.