Here are some popular VPNs for Android:

A VPN (Virtual Private Network) is a tool that allows users to connect to a remote server over the internet while controlling the content, traffic, and network settings. For Android users, there are several VPN services available that you can download and use to securely connect to various applications, websites, and services.

1. 1lvl - A free VPN that offers a wide range of features, including secure internet, file sharing, and remote desktop access.

2. Vpsdns - A popular VPN service that provides fast and reliable internet, as well as a range of features like file sharing and remote access.

3. Netnety - A cloud VPN service that offers 24/7 access to the internet, as well as a range of features for secure communication.

4. G packet - A free VPN service that provides a secure and private connection to the internet, with features like file sharing and remote desktop access.

5. Naghom - A popular VPN service that offers fast and reliable internet, as well as a range of features like file sharing and online banking.

6. G2 VPN - A free VPN service that provides a secure connection to the internet, with features like file sharing and remote desktop access.

7. OpenVPN - A free and open-source VPN service that allows you to connect to a remote server over the internet while controlling the content and traffic.

When choosing a VPN for Android, it's important to prioritize security and privacy. Look for services that provide a strong connection, fast speeds, and secure features. You can also check reviews and ratings for the VPN service you choose.

If you need a free VPN for Android, you can start with services like Pop3, HTTP, or G packet, which are all free and provide a good balance of security and functionality.