Sure, here are some of the best free calling apps for Android in 2024, based on factors such as call quality, features, and popularity:

1) WhatsApp

WhatsApp is one of the most popular messaging apps in the world, and it also offers free voice and video calling. WhatsApp calls are generally high quality, and the app also offers a number of features, such as call encryption, call recording, and group calling.

WhatsApp app

2) Google Meet

Google Meet is a free video-conferencing app that can also be used for voice calls. Google Meet calls are generally high quality, and the app also offers a number of features, such as screen sharing, recording, and live captions.

Google Meet app

3) Signal

Signal is a privacy-focused messaging app that offers free voice and video calling. Signal calls are encrypted, and the app also offers a number of features, such as disappearing messages, self-destructing timers, and group calling.

Signal app

4) Viber

Viber is a popular messaging app that offers free voice and video calling. Viber calls are generally high quality, and the app also offers a number of features, such as group calling, Viber Out (which allows you to call landlines and mobile phones), and Viber Games.

Viber App

5) Facebook Messenger

Facebook Messenger is a popular messaging app that offers free voice and video calling. Facebook Messenger calls are generally high quality, and the app also offers a number of features, such as group calling, video chat with up to 50 people, and the ability to share your screen.

Facebook Messenger app

6) Skype

Skype is a popular video conferencing app that can also be used for voice calls. Skype calls are generally high quality, and the app also offers a number of features, such as call recording, live translation, and group calling.

Skype app

7) IMO

IMO is a free video calling and instant messaging app that offers a number of features, such as group calls, voice and video messages, and disappearing messages.

IMO app

8) Messenger Lite

Messenger Lite is a lightweight version of the Facebook Messenger app that is designed for use on low-end devices. Messenger Lite offers free voice and video calling, as well as a number of other features, such as group calling, video chat with up to 50 people, and the ability to share your screen.

Messenger Lite app

9) Talkatone

Talkatone is a free calling and texting app that offers a number of features, such as free calling to the US and Canada, free texting to the US and Canadian mobile numbers, and the ability to earn free minutes by watching videos or completing surveys.

Talkatone app

10) TextNow

TextNow is a free texting and calling app that offers a free US phone number, free unlimited texting to any number in the US and Canada, and free unlimited calling Canada & USA on Mobile and Landlines.

TextNow app

11) Fongo

Fongo is a free calling and texting app that offers a free US phone number, free unlimited calling to landlines and mobile numbers in the US and Canada, and free unlimited texting to any number in the US and Canada.

Fongo app

12) FreePhone

FreePhone is a free calling and texting app that offers a free US phone number, free unlimited calling to landlines and mobile numbers in the US and Canada, and free unlimited texting to any number in the US and Canada.

FreePhone app

These are just a few of the many great free calling apps available for Android. When choosing a free calling app, it is important to consider your needs and budget. Some factors to consider include the call quality, features, and popularity of the app.

I hope this helps!