A free app for Android, by AppAzing.net.

eFTP is a free, powerful, and easy-to-use FTP client app for Android devices that enables you to easily connect to your servers using the FTP protocol. It supports both the TCP and the UDP protocols, and it has a built-in file manager that lets you browse through the files on your device and select the ones you want to transfer to the server.

It is very easy to use, and you can add as many servers as you want to the app and simply connect to them for uploading and downloading files. It supports both Wi-Fi and mobile data networks, and it has a built-in password manager that lets you create a password for launching the app and also add your fingerprint as the unlocking solution.