The Essential Features and Cost of building a Messaging App like Signal!

WhatsApp used to be the most popular messaging app, but not anymore, ever since its revised privacy policy was declared in January 2021. This policy asked users to share their personal information to Facebook. Needless to say, this declaration has adversely affected WhatsApp’s sky-high popularity as one of the most secure and encrypted messaging options. And, the Signal messaging app, which was earlier unnoticed by messaging app users, started to be adopted as the ideal replacement for safe messaging.

Signal has gained an undisputed reputation of keeping users’ chats and calls truly encrypted and private. Even high-profile users like Elon Musk, Brian Action, and Edward Snowden have endorsed Signal’s uncontested privacy quotient, because of the level of secrecy and security it offers.

Investing in a messaging app like Signal is a brilliant idea and many of you must have already started the app ideation process as well! So, this post explores the unique selling points of Signal, the necessary features to include while building a Signal-like app, and provides an approximate idea on signal app development cost.

Signal App: An overview

Signal is a cross-platform messaging application that follows the approach of app models like Red Phone and Text Secure. It has bagged the reputation of being the most encrypted and secure application available in the market. Signal, being open-sourced; its source code is available on GitHub and can be accessed easily.

Using Signal chat, users can avail of one-to-one messaging as well as group chatting in the most secure manner possible. Users can share images, voice notes, files, and videos and make video/audio calls without having to worry about the risks of account hacks or data breaches. The reason is that Signal adheres to highly encrypted messaging protocols like Double Ratchet Algorithm, Extended Triple Diffie-Hellman, HMAC-SHA256, Curve25519, and AES-256, to rule out any chances of MITM (man-in-the-middle) hacking attempts. Moreover, all calls and messages that take place over the app are end-to-end encrypted, such that even Signal cannot access users’ data. Furthermore, the app doesn’t allow users to take a screenshot.

This revolutionary app has been created by the Signal Technology Foundation and the Signal messenger LLC.

Signal’s Unique Functioning Protocol to ensure Security

Here’s how an encrypted messaging application works!

When the app is installed on a smartphone, a permanent key pair gets created. This key pair consists of a “public” and a “private” key that are meant to encrypt and decrypt messages. The process of encrypting and decrypting works like this – the “public” key is sent to the messaging server for identifying users and the private key stays within the users’ smartphones. And, if this private key is compromised, the users’ messages become vulnerable to security threats like decryption and misuse.

The Signal messenger uses a more secured protocol. It generates several temporary key pairs besides their permanent keys. This function empowers the app to change the key after each message. When a user sends a message to another user via Signal, it integrates the temporary and permanent pairs of public as well as private keys for both the users to create a shared secret key. This secret key encrypts and decrypts the message. And, as the private keys of users must be accessed for generating the secret key, the secret key stays only on the devices of the users involved in the messaging act.

Moreover, Signal adheres to the protocol of continuously replenishing keys for each user, and this function allows the app to acquire new shared keys after each message. Also, features like disappearing messages, turning off the lock screen notification option, blurred photos, and encrypted calls; tighten the app’s security further.

Essential Features to include in your Signal-like Chat/Messaging App

Real-time Messaging and Object Sharing

Real-time messaging is a core prerequisite; using this feature users enjoy real-time interaction from any part of the globe. The multiple object-sharing features enable users to share media, documents, contacts, and even their present location with other users either privately or via group messaging.

In-app Audio/Video Calling

The in-app audio/video calling feature is a must-have in messaging apps as it allows individuals across the globe to connect with each other from one single platform.

Privately encrypted chats

This functionality needs to be integrated into your messaging application as it restricts server access to metadata including chats, icons, titles, and membership icons.

Inviting Friends

Users should be able to invite their friends/acquaintances. So, your app should integrate “invite friends” feature that will request users to provide access to their contact details for inviting friends or acquaintances. This way, the users will be able to send the invitation link directly to the individuals they wish to add.

Disappearing Messages & Lockable Chats

The disappearing messages and lockable chat features provide users the flexibility to maintain the privacy of their personal life. Users can set a timer of their choice - 5 seconds, or even one week. After the end of the timeline chosen by the user, the messages will disappear automatically, without being stored in any cloud server.

“Delete for Everyone” feature

Signal allows one to delete messages (for everyone) unlike WhatsApp. Hence, users have the option to delete messages sent by mistake or simply if they wish to do so. So, integrating such a feature will attract users.

Voice over Internet Protocol

VoIP or the Voice over Internet Protocol feature is crucial as it offers a stable internet connection for ensuring an enriching communication experience, even during times of slower internet connectivity.

Support for Proxy Version

The proxy feature enables users to use the app seamlessly regardless of their location, even on instances when the app is blocked in some country. But, how? In Signal messaging, the proxy settings allow the user to make the necessary modifications for accessing the app since the data traffic remains opaque to the person who’s operating the proxy feature.

Signal App Development Cost: Guidance

Signal-like Messaging App Development: Factors that Affect the Cost

The cost of developing a Signal-like application depends on factors like the UI design of the app, the feature-set integrated into the app, the size of the development team, and the location of the development agency hired.

Signal-like Messaging App Development: Cost Calculation

Check out the average estimate of developing an app like Signal. If the hourly developer rates are 50 USD, the average signal app development cost for the iOS and Android operating systems can go upwards of 70,000 USD based on the location. Here’s the breakup of the timeline and developmental expenses!

For the Android OS: Timeline- over 900 to 1100 hours; Development Cost: Between 45,000 USD and 55,000 USD.

For the iOS OS: Timeline- over 800 to 900 hours; Development Cost: Between 40,000 USD and 45,000 USD.

App’s UI/UX design for a single platform: Timeline- over 80 to 100 hours; Development Cost: Between 5,000 USD and 7,000 USD.

App’s backend: Timeline- over 600 to 800 hours; Development Cost: Between 25,000 USD and 35,000 USD.

Now let’s take a look at the average signal app development cost based on the outsourcing region selected:

India: Hourly rate - between 50 USD and 70 USD; Average App Development Cost- 25,000 USD

Eastern Europe: Hourly rate - between 80 USD and 100 USD; Average App Development Cost- 40,000 USD

Western Europe: Hourly rate - between 90 USD and 120 USD; Average App Development Cost- 65,000 USD

Australia: Hourly rate - 100 USD; Average App Development Cost- 70,000 USD

North America: Hourly rate - between 100 USD and 120 USD; Average App Development Cost- 70,000 USD

Hence, outsourcing software development services to a development agency in India is the most profitable option.

Concluding Thoughts:

This post must have provided you with the necessary guidance on the USPs of Signal, its distinct way of functioning, and an average cost estimate of building a Signal-like messaging app. The development cost may vary as per the level of customization and complexity involved.

For developing a best-selling messaging app, it’s advisable to hire the services of an experienced and proficient mobile app development company like Biz4Solutions. We have helped myriad clients across the globe to build outstanding and futuristic app solutions for the past 10+ years.

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