Design a classified ads app like Haraj and OLX

The peer-to-peer marketplace has moved entirely to mobile: Today, users take a photo of their item with their phone and post it in seconds from wherever they are; they browse what’s for sale around them while waiting in line or riding public transportation; and they receive an instant notification the moment what they’re looking for becomes available. This is the power of a classifieds app that a website lacks—and it’s precisely what makes apps like Haraj and OLX dominate the screens of millions and be used daily. But most of those selling you an “ads app” are making a fundamental mistake: They build a scaled-down version of the website in app form, ignoring the fact that an app is a distinct entity that leverages the phone’s capabilities—notifications, geolocation, the camera—to become a daily habit, not just a page visited occasionally. A successful advertising app isn’t a website shrunk onto a small screen; it’s an experience built for the phone that leverages its unique capabilities to create a vibrant marketplace right in every user’s pocket.

In this guide, we’ll outline what your app really needs: Why an app is more powerful than a website in the directory, how to leverage the phone’s capabilities, how to build trust and combat fraud, how posting, searching, and communication work, what your revenue model should be, and how artificial intelligence can help you — and how we build all of that in Coderator.

1. Who is Coderator? And why do we build advertising apps differently?

Coderator is a software company specializing in building advanced business systems and integrating artificial intelligence into real-world operating environments. We operate from our offices in Giza and Riyadh to serve companies in the Middle East and North Africa. We treat the advertising app as a live marketplace in the user’s pocket that leverages the power of their phone—not a scaled-down version of a website. That’s why we don’t start with screens; we start with the equation that defines the success of any marketplace: How do we bring sellers and buyers together (liquidity)? How do we build trust in a marketplace where users fear scams? How do we leverage notifications, location, and the camera to make the app a daily habit? Then we build an app that masters this—with an experience designed for mobile, a trust system, and a clear revenue model. Most importantly: the code and your user base are entirely yours. Don’t remain hostage to a ready-made script that reaches its limits as your market grows, and don’t lose what you value most: your active user community.

2. Why is an app more powerful than a website for classified ads?

A website is excellent for accessibility and search visibility, but in the classifieds market specifically, the app has features that make it the primary driver of repeat usage. The reason is that classifieds are, by nature, a repetitive activity: users buy and sell frequently, constantly monitor their listings and responses from interested buyers, and search for new items posted every day. This pattern suits the app far better than the website. The app is always present as an icon on the user’s screen and sends instant notifications that keep bringing them back (a message on your ad, an offer on your item, a new ad matching your search), allows for quick posting via the camera in seconds, runs more smoothly, and fosters a daily usage habit.

That’s why all the major classifieds platforms (Haraj, OLX, Dubizzle) are betting on the app as their primary interface, while the website remains a complementary channel for search access. Anyone who builds you an app as a scaled-down version of the website wastes these strengths, resulting in a lackluster app that fails to retain its users. We build the app by leveraging its true strengths, because the difference between a successful classifieds app and an abandoned one lies in harnessing what makes the phone unique to bring the marketplace to life right in every user’s pocket.

3. The Phone’s Capabilities That Make the Difference

This is the essence of an app’s uniqueness—and what those who build a scaled-down version of a website overlook. We build apps to harness three capabilities that transform the classifieds experience:

These features aren’t just technical add-ons; they’re what make the app a dynamic experience tailored to the nature of a classifieds platform. Notifications encourage repeat use, the location feature makes the marketplace local and relevant, and live photography lowers the barrier to posting, filling the app with listings. We build these features into the very core of the app because they are precisely what set it apart from a website confined to a screen, transforming it into a daily habit in the user’s pocket.

4. The Challenge of Market Liquidity

This is the toughest challenge in any classifieds marketplace (whether an app or a website), and it’s one that script sellers tend to ignore. It’s a classic dilemma: buyers won’t frequent an app without enough ads, and sellers won’t post on an app without buyers. Technology alone won’t solve it; the solution is a launch strategy we’ll plan with you. Start with a specific geographic or category focus (a city or a category like cars or cell phones) to build real traction, rather than a general-purpose app that covers everything and remains empty. Fill the supply side first with quality listings, offer incentives to early publishers (temporary free posting and highlighting), and focus your marketing on your region or category to reach the critical mass at which the market begins to sustain itself.

This is where the capabilities of mobile devices play a role in accelerating liquidity: Live streaming makes publishing easier, increasing supply; notifications bring users back, boosting views and engagement; and geolocation makes even a limited number of ads seem plentiful because they’re relevant and close to the user. Anyone who sells you an app without warning you about the liquidity challenge is hiding the hardest part from you. We’re upfront with you about it and build app tools to support your strategy—because even the most beautiful app fails if it remains empty.

5. Rapid Publishing, Search, and Discovery

Two processes are at the heart of the app experience: the ease of posting an ad and the ease of discovering it. For posting, we build an experience that leverages the phone: easily taking photos directly with the camera or from the gallery, smart fields that adapt to the category (fields for cars differ from those for mobile phones or real estate), automatic GPS location detection, and posting in seconds. The easier it is to post, the more listings there are to fuel the market.

To make discovery easier, we’re building an enjoyable browsing experience optimized for mobile: fast search and rich filtering (category, price, location, condition, and specific features for each category), prioritizing nearby listings based on geographic location, seamless photo browsing, saving searches with instant notifications when a matching listing is posted (the app’s strength here is crucial), and sorting by newest or closest. The listing page builds trust and facilitates communication: clear photos, complete details, location on a map, seller information and ratings, and instant communication buttons (in-app chat, phone call, and WhatsApp). Easy posting and seamless discovery are what turn a casual user into a daily user who returns to the app whenever they want to buy or sell.

6. Trust and Fraud Prevention

This is the number one pain point in classifieds that makes or breaks an app’s success, just as it does for websites. Even major platforms have struggled with scammers, causing many to lose trust in them, so users approach with caution. An app that builds trust and protects its users earns their loyalty. We build a trust system at its core:

• Account verification: Identity verification (phone number via a verification SMS, and additional verification for active users), and a “Verified” badge.
• Ad review: Filtering ads to detect fake, duplicate, and stolen images, as well as violating content, before or after publication.
• Reporting and blocking: Enabling users to report suspicious ads or accounts, and smart blocking of repeat scammers.
• Ratings and reputation: Ratings for sellers and buyers to build a reputation that distinguishes the good from the bad and fosters trust.

A trust system is a prerequisite for survival, not a perk: An app rife with scams will be quickly deleted from users’ phones. Phone features also support trust: Verifying a phone number is easier and more reliable within the app, and geolocation helps detect fake ads from far away. We build trust at the core of the app because it is your strongest competitive advantage in a market plagued by scammers.

7. In-App Communication and Chat

Communication between sellers and buyers is the heart of the classifieds platform, and how it’s managed makes all the difference in trust and user experience. Many platforms allow communication to take place via exposed phone numbers, which compromises privacy and makes it difficult to resolve disputes. We’re building an in-app chat system: Both parties can communicate without revealing their phone numbers, with instant notifications for every message (which bring the user back to the app), the ability to send photos and location within the chat, and a communication history saved for reference in case of any dispute.

The in-app chat serves multiple purposes: It protects users’ privacy, keeps the interaction within your app (so users don’t switch to WhatsApp and lose track of the conversation), builds a record that helps resolve disputes and identify scammers, and encourages repeat use through notifications. It can also be linked to negotiations and offers (such as price quotes). This feature transforms the app from a static bulletin board into a vibrant marketplace where people interact—a hallmark of leading apps. We’re building this because seamless, secure communication is an essential part of the classifieds experience and of building trust.

8. User Account and Experience

In the Al-Mubawaba app, the user is both a seller and a buyer, and their account must serve both roles and keep them coming back. We’re building a comprehensive experience for them: managing their listings (active, expired, sold) with the ability to edit, renew, and upgrade to a featured listing; tracking their listings’ performance (views, replies, favorites) so they know what’s working; a unified chat inbox, a favorites list of ads that interest them, saved searches with instant notifications when a match appears, a balance wallet for purchasing premium services, and the ability to manage their data and verify their account.

We’re building the app with a mobile-first experience: smooth and fast, with intuitive visual navigation and lightweight performance that’s gentle on the user’s battery and data. The seamless mobile experience — one-tap posting, enjoyable browsing, helpful notifications, and secure communication — is what keeps users keeping the app on their phones and coming back to it whenever they want to buy or sell, transforming them from one-time users into loyal members of your marketplace. Building the app to be a daily habit—not a one-time tool—is the key to its success.

9. Admin Dashboard and Revenue Model

Behind the app is an admin panel that manages, secures, and generates revenue from it. We build it as a comprehensive control center:

Basic posting is often free to build liquidity, with revenue generated from value-added services, while the core value remains available to fuel the marketplace. The admin panel gives you control over your app, protects it from spam and scams, and helps grow its revenue. We tailor the model to your market.

10. Artificial Intelligence in Advertising

This is where we truly shine—AI tackles the toughest challenges in the ad space and elevates the user experience:

We’ve added these features to build market trust, protect quality, and truly enhance the user experience—all while ensuring your users’ data isn’t leaked to public training models. Note that image-based classification uses the phone’s camera directly, and location-based recommendations use GPS—integrating AI with the phone’s capabilities for a smarter experience.

11. Off-the-shelf solution or custom development? (When you don’t need a custom build)

Here, we’ll tell you what those who make a living selling scripts won’t: The decision depends on your stage and your ambitions:

• A ready-made script may be enough to quickly and inexpensively test a market idea on a small scale, so you can gauge demand before making a serious investment—use it wisely only during the testing phase.
• Custom development becomes a necessity when you’re serious about building a marketplace that grows and competes, because off-the-shelf scripts limit your customization options and offer limited tools for trust and quality (the essence of a successful marketplace), performance that stumbles as the platform grows, fails to fully leverage mobile capabilities, and leaves you without ownership of the code or your user base—so you’ll discover its limitations as soon as your marketplace grows and you have to rebuild.

We won’t push you to build a custom solution just to test an idea on a small budget—we might recommend a simpler solution first. But once the idea proves itself and you’re serious about building a real market—where trust, the phone’s capabilities, and your user base are the core of your success—custom development is an investment you own that grows with you without limits and without being tied to a script. We’ll help you make the right decision for your current stage in good faith, because your long-term success is more important to us than a single script deal.

12. Cost and Methodology

The cost of an advertising app varies depending on its scope, operating systems (Android, iOS), the extent to which the phone’s capabilities are leveraged, the complexity of the trust and communication system, the revenue model, quality assurance tools, and AI components. Therefore, it’s not appropriate to give a definitive figure before understanding your project, and anyone who gives you an immediate price without asking questions is selling you a script, not a solution. We start by understanding your business model, niche, user acquisition strategy, and revenue model, then we outline a clear picture of the costs and phases—and we recommend starting with a focused scope (a category or region) to establish traction before expanding.

Our approach recognizes that market success is commercial before it is technical: a discovery session where we define your business model, user acquisition strategy, and revenue model, followed by building a solid first version that leverages the power of the phone through a system of trust and conversation, followed by a limited-scope launch to build liquidity, then expansion through data integration and the addition of advanced tools (AI, new categories). We build a vibrant app that people trust and that engages users’ wallets—not just an empty script.

13. Frequently Asked Questions