Each sub-score is built from measured signals, normalized as percentiles across every category × storefront cell: a 70 means “better than 70% of lanes”, never a gut feeling. Percentiles are taken 75% against every cell and only 25% against the idea’s own storefront: grade a market purely on its own curve and a thin one looks as good as a deep one. Each card carries its exact weighted recipe.
Demand22% of the score
Is there measurable appetite in this category and market?
68%Category demand: regression-smoothed monthly rating growth across the free top-100, as a percentile of every category×storefront cell.
32%Leader’s size, capped: a big leader is proof the demand exists (the cap stops giants inflating it).
×Market value: US ×1 · UK ×0.71 · TR ×0.25 · DE ×0.65 · JP ×0.88 · KR ×0.94 · CN ×0.61. Demand is a prize, and a prize is smaller in a smaller, cheaper market. The multiplier is the square root of that storefront’s annual spend per iPhone user against the US’s, so it is derived rather than judged.
Winnability34% of the score
Can a small team actually take the lane from whoever holds it?
44%Beatable: the inverse of the leader’s size percentile. Small and mid-sized leaders are winnable; entrenched ones aren’t.
36%Leader is hurting: the worse of two live signals: a recent rating drop (lifetime average vs. current-version average) and the share of recent reviews at ≤2★. This is the only way the reviews we mine reach the score. Measured or nothing: an unmined leader scores zero here, never a default.
12%Chart churn: the average weekly turnover of the free top-100 across the month. Fluid charts admit newcomers.
8%Low entry wall: the inverse of the median rating count of the top-grossing apps.
×The hurting signal is damped by beatable (floor 0.35): anger at a small leader is far more actionable than anger at a titan, but a bleeding giant is a hard opening, not a non-opening, so it never damps to zero.
Monetization16% of the score
Do people pay here, and does the idea's model fit how they pay?
45%Grossing depth: how many charted apps monetize seriously (>20k ratings on the grossing chart).
30%Model fit: Subscription 0.95 · Credits / IAP 0.80 · Ads + IAP 0.80 · One-time 0.66 · Ad-supported 0.58.
25%Indie proof: count of top-grossing apps with <5k lifetime ratings. Small apps earning here is the canonical signal a solo dev can too (3+ = full marks).
×Run-cost multiplier: recurring COGS eat indie margin: none ×1 · low ×1 · medium ×0.93 · high ×0.82.
×Market value: US ×1 · UK ×0.71 · TR ×0.25 · DE ×0.65 · JP ×0.88 · KR ×0.94 · CN ×0.61. Until this landed, TR scored 62 here against the US’s 63, near-identical, though a TR user spends a fraction of what an American one does. It measured “does this category monetize relative to its own market”, never “how much money will I make”.
Feasibility18% of the score
How fast can one developer ship a credible MVP?
Solo build time to a shippable MVP: weekend 0.95 · week 0.86 · month 0.72 · quarter 0.45.
Older runs without a build-time token fall back to the effort class sniffed from the build note: light 0.92 · moderate 0.72 · heavy 0.45.
Momentum10% of the score
Is the lane heating up right now?
The leader’s grow potential: regression acceleration of its rating trend (0.5 steady, >0.5 speeding up): is the lane itself accelerating? Falls back to the category’s grow potential when no leader matched.
×0.9Shaved when a giant guards the lane: a giant’s tailwind is only partly yours to inherit.
Which storefront× multiplier
The same app is not worth the same everywhere. A win in a small, cheaper market is a smaller win, but it is no easier to build for, and the leader is exactly as hard to beat.
prizeIt scales Demand and Monetization, never Winnability or Feasibility. TR’s market is a twentieth of the US’s, yet the engine used to score it identically: Winnability handed it +13 for its small, beatable leaders while Monetization came out level, because it measured “does this lane monetize for Turkey”.
⚠A judgement, not a measurement. Apple publishes no revenue, so per-market spend cannot be derived from anything we hold. The UK is level with the US because a British user pays like an American one; its gap is size, and size barely binds a solo dev chasing a niche.
Giant penalty× multiplier
Going head-to-head with an entrenched leader is the classic indie mistake. Anchor size already sinks Winnability on its own, so this multiplier is a deliberate nudge on top, not a second full penalty.
⚠Anything over 700k lifetime ratings is also flagged Giant leader on the report, its lane’s momentum shaved ×0.9, and its modeled user reach halved.