The Momentum Index

全民K歌-你其实很会唱歌 added 6,415,055 new rating counts in this snapshot comparison, which works out to 67.9% of the 9,444,260 total across the top ten gainers list. My au, a Japanese telecom utility app, landed in second with 983,427, or 10.4% of that total, less than a sixth of what the karaoke app pulled in. After that things drop off quickly. MeinMagenta holds 5.6%, РосШтрафы sits at 4.3%, and Facebook closes out the list at 3.3%, barely a sliver compared to the leader. Growth clearly isn't spread evenly across these popular apps. One title, in one market segment, is soaking up engagement fast enough to make the rest of the top ten look almost stalled by comparison. A regional platform push or some kind of viral moment inside the Chinese social app market is probably behind it, since nothing else on the list comes close to that kind of surge. If you're scanning this list to spot rising categories, pull the karaoke app's number out first. Leave it in and that one outlier makes the whole list look far more dynamic than it really is, which can lead you to the wrong read on what's actually trending.

Across all 19,728 tracked apps, the average growth lands at 701.02, yet the highest recorded growth hits 6,415,055, more than 9,000 times that average. That gap shows the average isn't describing a typical app at all. A handful of extreme outliers pull the number upward while most apps barely move. Average volatility sits at 0.09, and this small figure points to the same story: for most apps in this population, average ratings hold steady between snapshots.

Put the two figures together and you can see the shape of the data. Rating counts spike hard for a few apps, but rating averages stay fixed for nearly everyone else. You need that asymmetry to read the data correctly. A burst in raw rating counts usually traces back to a single trigger event, a spike in engagement, while the average rating resists quick change even when volume surges. If you're building a momentum score from this data, treat count growth and rating volatility as separate signals: one is rare and spiky, the other stays calm and largely uniform across the 19,728 apps tracked.

Look down the top-decliners list, from Hadist Shahih Lengkap to Way of the Hunter Wild Europe to TCL TV Remote, and every single one shows a rating count of 0. Ten apps share that exact number, and there's nothing tying them together on paper: religious reference tools, weather apps, a soccer game, a QR generator. None of them slid down by a little or a lot compared to the rest. They're all just sitting at zero. That's worth pausing on, because it doesn't look like a slow bleed. A gradual decline would show apps losing ratings they'd already banked. This isn't that. These apps simply stopped picking up new ratings between snapshots. Given that the list spans prayer apps, remote-control utilities, and a niche sports title, a category-specific explanation doesn't hold up. What we're likely looking at is a lifecycle problem: these apps went quiet, dropped out of visibility, or got deprioritized somewhere along the way, rather than actively losing engaged users. So if someone's using this list to call out "declining" categories, that's the wrong read. Zero growth spread across such an unrelated group of apps points to individual apps going stale, not a downturn hitting a whole category.

Entertainment posts a growth score of 6,549.0, more than five times the next category, Social Networking, which sits at 1,232.8, and over five times Utilities at 1,198.7. Productivity comes in further back at 810.8. Medical lands at the bottom of the list with a score of 186.1, roughly a 35-fold gap from the top category. Worth remembering: these are growth scores, not counts, so adding them up or converting them into shares of some bigger pool just doesn't work. Even so, the ranking tells a real story. Entertainment's massive lead traces straight back to the concentration we saw in the top-gainers list, where a single karaoke app dominated raw rating-count additions, and the Entertainment category classification appears to be soaking up that same surge. Music (218.2) and Medical (186.1) sit near the bottom, suggesting steadier, lower-amplitude engagement in those spaces, free of the viral spikes that can drag a whole category's growth score upward. Anyone watching category-level momentum should take away one thing from this: a category's aggregate growth score can just as easily be an artifact of one or two breakout titles as proof of broad-based category health. Rankings built this way need a cross-check against individual app data before anyone treats them as evidence of a category-wide trend.

Developer Tools posts an average-rating volatility score of 0.5, which is roughly two and a half times what Graphics & Design and Sports show (both sitting at 0.2), and five times the reading you get from the pack parked at 0.1: Food & Drink, Reference, Navigation, Social Networking, Weather, Music, Utilities, Business, and Travel. Nine of the twelve categories here land on that exact same low number, so ratings across most consumer-facing app categories just don't shift much from one snapshot to the next. Developer Tools stands out because of who's actually using these apps. It's a smaller, more technical, more opinionated crowd, and a single bad update or breaking change can send ratings swinging in ways a weather app or music app never has to deal with. Graphics & Design and Sports sitting at double the baseline volatility tells a quieter version of the same story: people in those niche or feature-sensitive categories react a little more sharply than the folks using the broad utility categories underneath them. If average-rating instability is your early warning signal, watch Developer Tools closely. Travel, Music, and Utilities aren't going anywhere no matter what happens.

Free apps post a momentum score of 758.6. Paid apps sit at 13.8. That gap is stark, and paid app momentum barely registers next to it. It's a pattern that shows up everywhere else in this study too: the top-gainer list, the category growth rankings, the overall average growth figure, all of it traces back to high-volume, low-friction engagement. Free apps just fit that mold better. Paid apps need a purchase before anyone can even leave a rating, which shrinks the pool of people who'll ever bother reviewing them. A free app, on the other hand, lets anyone grab it and rate it on a whim. That friction gap explains the 758.6 versus 13.8 split far better than any difference in quality or satisfaction would, since this cut measures momentum, not how good the ratings actually are. If you're a developer or analyst tracking this metric, here's the takeaway: when rating-count momentum is your yardstick, pricing model carries much of the weight before content quality or marketing even enter the picture. Paid apps hit a lower volume ceiling here, and it has nothing to do with quality. Compare their momentum score against free apps without accounting for that ceiling, and paid software will always look stagnant, even when it isn't.