How to Build a Secure Messaging App Like Signal?

Updated on Jul 1st, 2021

Technology has changed the way we communicate with others. Instead of paying hefty charges for international calls, we can now connect with anyone from anywhere just with the help of the internet. Thanks to these messenger apps. You can use these messenger apps to send texts, photos, videos, files, video/audio calls, etc. There are a number of factors that gave massive popularity to these messaging apps like Signal.  

On the other hand, there are some points that make us think about these apps. The internet is a heavily crowded place, and people are always concerned about their privacy and data security. Many of these messenger apps fail to deliver security to the users; often, it is heard that a certain company leaked the data of its customers. In these times, there is a high demand for a secure messaging app that can guarantee the security the user needs.  

The security concern arises due to mishandling of the customer’s data by these companies, sometimes it’s disturbing. Signal has come to the limelight due to its high-level security features and data privacy; users have been searching since the beginning of the internet revolution. Numerous entrepreneurs are investing in secure messenger app development these days, and you should think about it too. The messaging app market is brimming with opportunities, and it is the correct time to dive in and leave your mark.

Market Landscape

The global market of messenger app development is flourishing every day. According to a report of global news wire, the number of users of messaging apps will increase to a massive figure of 2.7 million by the year 2027. These apps have gained a significant amount of growth in terms of users and revenue during the period of the COVID-19 pandemic. In the year 2020, the total number of users was around 1.7 billion users, and it is expected to grow at a CAGR of 6.9 percent between the period 2020-2027. 

The U.S. has a majority in the number of users of these messaging apps, with a total figure of 461 million users in the year 2020. However, China is expected to cross the mark of 592 million users by the year 2027, with a CAGR of 10.04 percent. 

Apart from these major contenders in terms of the user base, Japan and Canada will experience an increase in the number of messaging app users at a CAGR of 3.7 and 6.1 percent, respectively. On the other hand, Europe is expected to experience an increase of 4.4 percent. In terms of security, the global messaging security market is expected to cross the valuation of 11.10 billion U.S. dollars by the year 2025 at a CAGR of 13.7 percent. The market seems promising; let’s understand the game-changer of the messaging app industry: Signal. 

Signal: What is it, and How it Works?

The Signal can be described as a cross-platform instant messaging app that is free to use for users. The main attractive feature of Signal is its centralized encryptions that use the internet to send various files across the network, such as photos, videos, files, etc. Users feel a sense of security while using this app. The Signal was somewhere hidden on the internet until Tesla’s founder Elon Musk tweeted about this app. Since the two-word tweet of Elon Musk, Signal’s popularity and the number of downloads got an instant boost. 

Signal Technology Foundation and Signal Messenger LLC have developed this most secure messaging app. Since its launch, it has been considered the most secure messaging app in the world and has been serving as a role model for other messaging apps in terms of security and privacy. 

The working of Signal is pretty simple to understand. In other apps, the messages are exchanged between the users through a server, but without any encryption, the messages will be transferred as plain text, which makes them prone to cyber-attacks. Whereas, in the case of Signal, it sends the message between two parties with encryption that convert the message from the sender into cyphertext that is an encryption with a key. After the message reaches the recipient, it is converted back into plain text with the help of a paired key. 

The important thing about encryption keys is that they are not stored on the server. Instead, they are stored in the recipient’s device. This form of security delivers a proficient level of privacy as the messages can be read only by the sender and the receiver, not by the service provider. Signal uses various cryptographic protocols such as Extended Triple Diffie-Hellman (X3DH), Double Ratchet algorithm, Curve25519, AES-256, HMAC-SHA256, etc.

Secure Messenger App Development Process   

The process of developing an app like Signal is indeed full of challenges, but it is not that difficult as you think. With proper planning and mapping of an efficient roadmap, you can develop a flawless secure messaging app that can be the next Signal. Any messaging app development process relies on three major factors, research, planning, and the technology stack involved in the project. Let’s start with the research process.


The initial step of any successful project is research. You need to know about the market space and the current trends that are subject to change. A deep research will tell you a ton of beneficial facts about the market that will help you understand the demographics of the industry. Start with your competitors, know everything about their implementation strategy, business plan, and marketing strategy. You will come to know about various insights that will fuel your ideas.

After the competitors, research about the market’s most reputable mobile app development company and their services. Ultimately, you will need a development partner to execute your idea. Learn about these company’s various hiring models and which suits you the most. The next step involves knowing your audience, get to know the expectations of the users from a new secure messaging app. Remember, fulfilling the user’s expectations can get you a massive popularity. After gathering every necessary fact, proceed to the next step: carving a road map.


Now that you have gathered a useful set of data, it’s time to whip up an intelligent plan. Start with the decision of platforms, whether you want to develop your platform on iOS or Android or both. Remember, a cross-platform secure messaging app is more successful than a single platform app. It’s a major decision, and you should have a session with your in-house team.

The next step involves making the app engaging. Integrating extraordinary features that awe the customers is an innovative way to enhance the engagement of your app. You should have a set of result-oriented features integrated into your app that will enhance the user’s experience. Some of the most effective features of a secure messaging app, excluding onboarding and creating user profiles, are:

Disappearing Messages: Your app should have a feature that allows users to set a timer to auto-destruct or delete messages. Integrating this feature can take privacy to the next level. You can ask your mobile app developers to restrict the screenshot function in your app.

Audio/Video Calls: Your app, like Signal, should deliver a flawless quality of the audio and video calls to the users. Please ensure to make these calls as secure as possible to add an extra level of comfort to your user’s experience.

Group Chats: It is an essential feature in any messaging app and should be present in your app. You can deliver secure one-to-one chats on your platform and allow users to choose whether they want to encrypt their messages or not. Make sure your app has no data stored in these groups.

Content Sharing: Don’t limit your app to only transfer text and audio; your app should allow users to share various types of content such as audio, video, text, photos, GIFs, documents, etc. Delivering an extra level of feasibility will enhance the reputation and popularity of the app.

Enhanced Security: The single reason for the popularity of an app like Signal is security. You should deliver an esteemed level of encryption and security in your app. You can deliver the users a section where they can create a private chat that will be highly encrypted and will self-destruct with the help of a timer. In order to implement security protocols, you can use Telegram API.

Tech Stack & Cost to Develop  

A proficient technology stack can enhance the performance and usability of your secure messaging app. Signal has a simple yet effective tech stack that fuels the performance of the app. You can ask your development partner to integrate the best tech stack as per the type of features and your expectations from the platform.

If you want, you can also just follow Signal as a reference and use the same tech stack with some changes. There are various languages and frameworks that are necessary for an app like Signal’s development, such as JavaScript, jQuery, Python, PHP, NGINX, Java, Apache HTTP Server, Ubuntu, CSS 3, Ruby, Go, Objective-C, Shell. etc. For the purpose of various utilities, you can consider using Twilio SendGrid, Disqus, Dyn, Piwik, etc. In terms of analytics and tracking the business performance, you can use Gmail, WordPress, G Suite, HubSpot, etc.

There are various APIs available in the market that will make your app’s features functional. You can consider using APIs such as Telegram API, Signal API, Bulk SMS Gateway API, WhatsApp Business API, Twilio SMS API, BDApps Pro SMS API, Verizon ThingSpace SMS API, Telenor SMS API, waboxapp API, etc.

The cost involved in your app’s development will depend on a number of factors. To get an exact estimate, you have to get in touch with your development partner. The number of features you want to integrate into your app will affect the cost of development. The decision of platforms will have a huge impact on the budget of your messenger app development process. Single platform development is less expensive than cross-platform development.

However, you’ll get a wider user base with cross-platform development. The location of the development will fluctuate the cost of development. Overall, you have the authority to control the budget of your app’s development process. Various companies deliver feasible hiring models that will help you in developing a flawless app within your decided budget.

How to Make Money With Your Secure Messenger App like Signal?  

An app like Signal has been developed by the Signal Foundation: a non-profit organization. Since the app was created to deliver a proficient level of security and privacy to its users, it does not have any traditional method of money-making. However, the foundation does attract hefty donations from various tech giants around the world. Unlike Signal, you can make money from your app by implementing various traditional ways such as:

In-app Purchase: You can offer users various services and premium features on the platform and charge a fee for the same. This business model is followed by various giants of the messaging app industry.

Advertisements: The most common and effective way of making from any mobile app is advertisements. Since you are developing a messaging app, you can display ads of various top companies on your app in various sections. You can charge a fee to display an advertisement on your platform. Don’t overdo it; users often get irritated with too many ads.

Subscriptions: Users can choose a subscription on your app for various services. You can create a private messaging section with added features and offer an affordable subscription to the users.

The Final Takeaway  

The secure messaging app market is booming with opportunities and will continue to grow. An advanced level of security and privacy are the most demanded features in any messaging app these days. Understand the users’ requirements and deliver them top-notch features and feasibility, and who knows, your app can be the next big thing.

The team of highly skilled engineers at Matellio can help you build your dream messaging app like Signal. We have been serving our clients with flawlessly engineered mobile apps and software for more than 15 years. With vast professional experience and learning, we can deliver you the app of your expectations. We offer a range of feasible hiring models that suits your varying needs. We offer a 30-day free maintenance period to all of our clients. Talk to our experts about your idea; fill the form now!

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