There are various messaging apps similar to Telegram. Some popular ones include WhatsApp, Signal, Discord, and Viber. Each has its own unique features and security options. If you want a custom messaging app, consider working with an app development company.

Signal is considered safer than Telegram because it offers end-to-end encryption as a primary feature to secure all the messages. To develop secure messaging apps, you might want to look into custom Android app development or custom iOS app development services.

WhatsApp is one of the best free chatting apps. It’s user-friendly, widely used, and offers end-to-end encryption. If you need a versatile app for both Android and iOS, hybrid mobile app development might be a good choice.

Apps like Telegram, WhatsApp, and Signal usually require a phone number to register. However, applications such as Kik and Skype enable users to sign up without requiring a phone number.

You can chat without a SIM card by using apps like Telegram, WhatsApp, or Signal over Wi-Fi. Just download the application on your device, register using your phone number, and then switch to using Wi-Fi. For building such apps, a react native mobile app development service can be ideal.