Key Takeaways

• The best SaaS ideas usually fix a small, specific gap in a platform its own users already complain about.
• App marketplaces hand you a built-in audience and proof people already want the fix.
• This list covers 53 marketplaces, each with a real example of a problem a third-party app was built to solve.
• Budget for the marketplace’s revenue cut, request minimal permissions, and build your own site and email list.
• Keep your app compatible with platform updates (missing one got Aurajinn’s first Shopify app pulled from the app store).

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If you’re looking for a SaaS business idea, there’s no shortage of problems to solve – the real challenge is knowing where to look. 

The global SaaS market is projected to reach $465 billion in 2026, and the average company now runs somewhere between 130 and nearly 300 separate software tools just to operate day to day. 

That’s the tension worth sitting with: with that much money and that many individual apps already in play, no single platform can possibly build every feature every user asks for. So where do you find proof that other people are hitting the same wall you are, and what does it actually take to build the fix?

What Makes a Good SaaS Idea?

Many first-time founders assume they need a completely original idea to build a successful SaaS product. In reality, some of the most profitable software businesses solve small, specific problems that larger platforms overlook.

A good SaaS idea usually starts with a recurring frustration. Maybe a task takes too many clicks. Maybe two tools don’t work well together. Maybe a platform lacks a feature that users repeatedly request. If enough people experience the same problem, there may be an opportunity to build a solution.

You don’t need a formal market research report to find these opportunities. Pay attention to the software you already use. Every workaround, spreadsheet, manual process, or missing feature could point to a problem worth solving.

One of the easiest places to spot these gaps is inside established software ecosystems. Large platforms can’t build every feature their users want, so they create app marketplaces that allow third-party developers to fill the gaps.

The platforms below have active marketplaces, large user bases, and ongoing demand for new apps. Each one represents an opportunity to solve a specific problem for an existing audience rather than trying to build software from scratch and hope customers show up.

You might also like: How to Validate an Online Business Idea Before You Waste Months Building it

54 App Marketplaces Where You Can Find SaaS Opportunities

Here, we spotlight eight platforms with real, documented gaps then share 40+ more marketplaces where you might find an opportunity that could use a SaaS solution.  

1. WordPress Plugins

Core has never shipped real SEO controls: no meta description fields, no sitemap, no on-page guidance. Yoast SEO was built to close exactly that hole and became one of the most-installed plugins in WordPress’s history. → WordPress Plugin Developer Handbook 

You can’t spot a gap like this from a review article. You have to be inside the WordPress dashboard, watching where the SEO fields should be and aren’t. To get your own WordPress site running and start poking at what’s missing before you write a line of plugin code, set up WordPress hosting first.

2. Shopify App Store

Native checkout has no real support for discounted product bundles; merchants have to bolt on a third-party app just to sell “buy 3, save 15%” the way most shoppers expect. That’s exactly the gap apps like Bold Bundles and Zoorix were built to close. → Shopify App Development 

Reading about the bundle-pricing gap isn’t the same as hitting it yourself at checkout. Open a real Shopify store, try to build a “buy 3, save 15%” offer with only native tools, and you’ll find the edges of the problem faster than any writeup can describe them. To give it a shot, start your free Shopify trial.

3. WooCommerce Marketplace

Core WooCommerce has no built-in abandoned cart recovery, so a store owner has no automatic way to follow up when someone loads a cart and leaves. That gap, like others, is exactly why recovery-focused plugins exist purely to send that one follow-up email native WooCommerce can’t. → WooCommerce Developer Resources

The abandoned-cart gap only becomes obvious once you’re staring at your own store’s checkout funnel and realizing nothing follows up automatically. To spin up a live WooCommerce store and watch a real cart get abandoned before you decide how you’d fix it, get started with WooCommerce.

4. GoHighLevel Marketplace

GoHighLevel’s native messaging runs through standard SMS, but agencies managing client accounts constantly get asked to support iMessage and WhatsApp too, channels the CRM doesn’t handle out of the box. Apps like myCRMSIM were built specifically to add that channel coverage on top of GoHighLevel’s core CRM. → GoHighLevel Marketplace Developer Docs

If you want to test the CRM so you can think of a good build project, start with a 30 trial of HighLevel Bootcamp.

5. Box Integrations

Box is pure cloud storage with no native document editing or e-signature tool built in, so it leans on roughly 1,500 third-party integrations to handle anything beyond storing and syncing files. Apps built specifically to add that missing editing/workflow layer are exactly what fill the gap. → Box Developer Console

You won’t notice what Box can’t do until you’ve actually tried to get a document signed or edited inside it. To sign up, run a real file through a real workflow, and get the missing piece to show itself, try Box free for 14 days.

6. Semrush App Center

Semrush’s core tools show you keyword volume, but they don’t natively flag which of your competitors’ ranking pages are actually weak — thin content, slow load times, missing keywords in the title. The SERP Gap Analyzer app was built specifically to surface those under-optimized pages as low-competition opportunities. → Semrush App Center Developer Docs

The SERP Gap Analyzer opportunity is easy to describe and hard to really see until you’re the one running the audit. To get into Semrush yourself, pull a real competitor report, and watch for the exact moment the tool tells you less than you need to know, try Semrush free for 7 days.

7. Todoist Integrations Directory

Todoist has no native way to turn a completed task into a billable time entry — a real gap for freelancers and consultants tracking hours. Third-party apps exist purely to convert finished Todoist tasks into invoiceable time. → Todoist Developer Documentation

The billable-hours gap is invisible until you’re a freelancer closing out a project and realizing your finished tasks have nowhere to become an invoice. To run your own work through Todoist for a week and try to feel exactly where that handoff breaks, get started with Todoist.

8. Slack Marketplace

On the free tier, message search only covers the last 90 days, so institutional knowledge just quietly vanishes. Question Base was built specifically to capture and permanently index Slack Q&A before it disappears. → Slack API Platform

9. Chrome Extensions

When YouTube pulled the public dislike count in 2021, a lot of people relied on it to gauge video quality before clicking. The “Return YouTube Dislike” extension exists purely to put that number back, and it’s one of the most-installed extensions in the Web Store. → Chrome Web Store Developer Dashboard

10. HubSpot Marketplace

There’s no native deduplication tool beyond manually merging contacts one at a time, a pain point that shows up constantly in HubSpot’s own community forums. Apps like Insycle and Dedupely exist purely to clean up duplicate CRM records at scale. → HubSpot Developer Platform — or if you’d rather recommend the CRM itself, [get started with HubSpot here] (insert your affiliate link).

11. Zoom Marketplace

No native meeting notes or action-item capture, so someone’s always manually typing while everyone else talks. Otter.ai and Fireflies.ai are both official Zoom Marketplace apps built to auto-transcribe and summarize instead. → Zoom App Marketplace for Developers

12. NotionApps

You can build a database, but you can’t natively turn it into a chart or graph. Several third-party widget tools exist purely to add that missing visualization layer. → Notion Developers 

You might also like: Aurajinn vs Notion: Which one Actually Gets Your Business Launched? 

13. Discord Apps

No built-in moderation, leveling, or welcome-message system once a server grows past a handful of people. MEE6 and Dyno were both built to fill that exact gap and are now two of the most-added bots on the platform. → Discord Developer Portal

14. Wix App Market

Wix’s native site editor doesn’t include a real booking or appointment-scheduling system out of the box, so service-based businesses (salons, tutors, consultants) have had to lean entirely on third-party apps to handle that core function. → Wix Developers Center

15. BigCommerce App Marketplace

BigCommerce ships with a genuinely deep feature set, but subscription billing and recurring payments aren’t native — a merchant who wants to sell a subscription box or membership has to install a third-party app to make it work at all. That’s not a minor gap; it’s a real category of merchant that BigCommerce’s core product simply doesn’t serve on its own. → BigCommerce Developer Portal

16. Webflow App Marketplace

Webflow has no native multi-language support, which is a real blocker for any business operating across countries or regions. Tools like Weglot exist purely to bolt on translation and a language switcher that Webflow’s core editor doesn’t offer. → Webflow Developers 

17. Squarespace Extensions

Squarespace has no native way for site visitors to upload their own files — a real problem for photographers collecting client proofs, agencies collecting documents, or anyone running an intake form that needs an attachment. Third-party uploader extensions exist purely to add that missing capability. → Squarespace Developer Platform

18-22. CRM & Customer Support

• Salesforce AppExchange — the largest, longest-running B2B app marketplace. → Salesforce Developers
• Zendesk Marketplace — ticketing, live chat, and telephony add-ons. → Zendesk Developer Docs
• Intercom App Store — customer engagement and chatbot integrations. → Intercom Developer Hub
• Freshworks Marketplace — apps across Freshdesk, Freshsales, and the rest of the suite. → Freshworks Developer Portal
• ServiceNow Store — enterprise workflow and ITSM apps. → ServiceNow Developer Program

23-27. Collaboration & Productivity

• Google Workspace Marketplace — add-ons for Docs, Sheets, Gmail, Drive. → Google Workspace Marketplace SDK
• Microsoft AppSource — apps for Microsoft 365, Dynamics 365, Power BI. → Microsoft Commercial Marketplace
• Atlassian Marketplace — plugins for Jira, Confluence, Trello. → Atlassian Developer Platform
• monday.com Marketplace — workflow widgets on the Work OS. → monday.com Developers
• Asana — integrations for project and task management. → Asana Developers

28-33. Infrastructure & Developer Tools

• AWS Marketplace — cloud software listings sellable to AWS customers. → AWS Marketplace Management Portal
• Google Cloud Marketplace — deployable solutions for GCP. → Google Cloud Marketplace Partner Docs
• Azure Marketplace — same submission path as Microsoft’s other commercial marketplace apps. → Microsoft Commercial Marketplace
• GitHub Marketplace — apps and Actions for the GitHub ecosystem. → Building GitHub Apps
• Stripe App Marketplace — tools embedded in the Stripe Dashboard. → Stripe Apps Documentation
• Zapier — the integration layer connecting everything else on this list. → Zapier Developer Platform

34-37. Browser Marketplaces

• Firefox Browser Add-ons — Mozilla’s extension ecosystem. → Firefox Extension Workshop
• Microsoft Edge Add-ons — Chromium-based, separate submission from Chrome. → Microsoft Edge Add-ons Developer Dashboard
• Safari Extensions — distributed through the Mac/iOS App Store. → Apple Safari Extensions
• Opera Add-ons — smaller audience, lighter review process. → Opera Add-ons Developer Portal

38-42. Email & Marketing Tools

• Gmail Add-ons — apps that live inside the Gmail sidebar. → Gmail Add-ons Developer Guide
• Outlook Add-ins — the Microsoft equivalent for Outlook. → Outlook Add-ins Documentation
• Mailchimp Integrations — apps connecting to Mailchimp’s marketing suite. → Mailchimp Developer Portal
• Klaviyo App Marketplace — integrations for Klaviyo’s e-commerce-focused email/SMS. → Klaviyo Developer Portal
• ActiveCampaign Marketplace — apps for ActiveCampaign’s automation platform. → ActiveCampaign Developer Docs

43-46. Design & Creative Tools

• Figma Community/Plugins — plugins and widgets inside Figma files. → Figma Developers
• Canva Apps — apps embedded directly in the Canva editor. → Canva Developers
• Adobe Exchange — extensions across the Creative Cloud suite. → Adobe Developer Exchange
• Airtable Marketplace — apps and automations for Airtable bases. → Airtable Developer Marketplace

47-49. Code Editors

• VS Code Marketplace — the largest code-editor extension ecosystem by far. → VS Code Extension API
• JetBrains Marketplace — plugins across IntelliJ, PyCharm, WebStorm, etc. → JetBrains Marketplace Docs
• Obsidian Community Plugins — plugins for the note-taking app’s local-first ecosystem. → Obsidian Plugin Developer Docs

50-52. Finance & Payments

• Intuit/QuickBooks App Store — apps connecting to QuickBooks accounting data. → Intuit Developer Portal
• Square App Marketplace — apps for Square’s point-of-sale ecosystem. → Square Developer Platform
• Xero App Marketplace — apps for Xero’s small-business accounting suite. → Xero Developer Center

53-54. Events & Voice

• Amazon Alexa Skills Store — the one voice-assistant marketplace still genuinely open to new developers. → Alexa Skills Kit
• Eventbrite App Marketplace — apps that plug into event creation, ticketing, and promotion. → Eventbrite Platform & API

What to Avoid When Building Your First SaaS on a Marketplace

App marketplaces can put your product in front of people who already use the platform you build for. That can make customer discovery easier, but you still need to do your homework before you write code.

App marketplaces can put your product in front of people who already use the platform you build for. That can make customer discovery easier, but you still need to do your homework before you write code.

So, don’t skip:

• Platform research. Make sure people actually have the problem you want to solve. Read reviews, community posts, support threads, and feature requests to see whether the same pain point comes up again and again.
• Platform updates. APIs, requirements, and marketplace policies can change. Check your email and developer notifications, then update your code when the platform changes. This is how Aurajinn’s first Shopify app ended up removed from the platform. We missed an important update and didn’t make the required changes in time.
• The marketplace’s revenue share. Many platforms take a percentage of each sale. Some take 15% to 30% or more, depending on the platform and transaction. Factor those fees into your pricing before you launch so your margins still work after the marketplace takes its cut.
• App permissions. Ask for only the access your app actually needs. Marketplace reviews can flag apps that request unnecessary permissions, and users may hesitate to install an app that wants access to more data than expected. So, as a rule of thumb, keep your permissions as narrow as possible.
• Your own distribution channels. Marketplace search can bring you customers, but you don’t control the algorithm, fees, review rules, or platform policies. Set up your own website and start building an email list from the start. Even a small audience you control gives you another way to reach customers if the marketplace changes.

A marketplace can give you a head start, but you still need to build a business around your app. Validate the problem, keep your product compatible, understand your costs, and create ways to reach customers outside the platform.

Final Thoughts

You don’t need to invent something the world has never seen. You need to notice a gap that already frustrates real people, inside a platform that already has an audience, and build the fix. That’s the throughline running under every entry on this list — from Yoast SEO closing a hole WordPress never filled, to a simple app that turns a finished Todoist task into an invoice. None of those builders waited around for a flash of inspiration. They paid attention to what already annoyed them and started there.

The 53 marketplaces above are really just the fastest way to find that starting point. Each one comes with a built-in audience, a documented history of feature requests, and a review process that tells you almost immediately whether your idea has legs. This can be a faster, cheaper way to validate a SaaS idea than any market research report could give you.

But finding the idea is only the first step. You still have to price it correctly, keep your app compliant as the platform changes, and build a way to reach customers that doesn’t live or die by someone else’s algorithm. That’s usually where first-time builders get stuck (not on the idea itself, but on everything that comes after it).

To turn today’s annoyance into tomorrow’s launch plan, claim your free Aurajinn launch dashboard today.