BuildOn Marketplaces
For software builders · every Monday

Don't build and hope. Find the marketplace first.

Buyers already gather in app stores and marketplaces, ready to pay. We show you which one fits what you build, what they pay for, and what's missing, before you write the code.

Have an idea? Reply to any issue with it and we may pick it for a teardown.

Marketplace check

  • Crowd66,301 listings in our first snapshotEvery public Actor in the store, 14 Sep 2026strong
  • SpendPay per eventNo rental pricing from 1 Oct 2026clear
  • GapsCategory by category in the AtlasListings and usage side by sidemapped
  • FitData tools one builder can maintainOur read, from our own buildsour read
  • Receipts3 builds liveFollow them belowrunning

Sources: our Atlas snapshot, 14 Sep 2026 · our note on rental pricingRead the Apify research →

  • Crowd~1.75M merchants, 17,591 apps~550 new apps a monthstrong
  • SpendKeep 100% of your first US$1M15% share above that; stores run 6–8 appsstrong
  • GapsReview scan in progressLands in the Monday issuescanning
  • Fit~80% of developers list one appA single focused app can competeopen
  • ReceiptsNo build yetnone

Sources: Craftberry, Apr 2026 · Meetanshi, Jan 2025 · shopify.dev revenue shareGet it on Monday →

The usual order
  1. Build
  2. Launch
  3. SEO and ads
  4. Hope someone pays
Our order
  1. Marketplace
  2. Demand
  3. Niche
  4. Build
  5. Sell

The method

Five questions, asked in order, before anything gets built

Every guide, teardown and build on this site answers the same five. If a marketplace fails the first two, nothing after them matters.

  1. Crowd

    Is anyone there? Buyers, installs, traffic, listing counts.

  2. Spend

    Do they pay, and how? Pricing models, revenue share, payouts.

  3. Gaps

    What do they ask for that nobody sells yet? Reviews, requests, thin categories.

  4. Fit

    Can you serve that gap? Your skills, at a cost that works.

  5. Receipts

    What happened when we tried it? Our builds, with what we learned.

What's possible

Small teams already win here

Builders who picked the marketplace first, read through the same five questions. Public figures only, each linked to its source.

Shopify App Store

Lightward (Locksmith)

Maker of Locksmith, one of the first 100 apps in the store. A team of 12, no investors, past US$23 million in revenue, serving 19,000+ merchants.

Source: Shopify →
Teardown slot

Next: an Apify publisher

Picked from the Atlas by usage, then read through the five questions.

Get it on Monday →
Teardown slot

Next: a Chrome extension

A solo-built extension with public numbers, and the gap it filled.

Get it on Monday →

Our builds

The framework, worked in public

We run the five questions on our own builds: why this marketplace, what we expect, what we built, and what happened, including the ones we drop.

StreamsKinds
LaunchApify2026-09-19

AI Search Visibility Action Plan is live

AI Search Visibility Action Plan launched on the Apify Store: can ChatGPT and Perplexity find your business? One report says what they answer about you, what is stopping them, and the three things to fix first — US$4.95 on your own keys.

BuildingApify2026-09-16

We pointed our third Actor at our own site. It found three things.

The AI Search Visibility Action Plan is built and in its private test: twenty runs on our own two domains, every plan grounded, no key in any output. On buildonmarketplaces.com it found no JSON-LD, no profile links and no sitemap — and neither engine names us yet.

LaunchApify2026-09-14

SEC Account Briefs is live

SEC Account Briefs launched on the Apify Store: A decision-ready account brief for any company on your watchlist — every sentence cited to an SEC filing.

LaunchApify2026-09-14

SEC Event Intelligence is live

SEC Event Intelligence launched on the Apify Store: Evidence-linked business events from SEC filings — classified, quoted, and cited — for the companies you track.