A free app for Android, by Kunal Applications.

Call Cube: a hidden automatic Call Recorder is a free tool that allows you to record all incoming and outgoing phone calls with the option to record conversations with your VOIP provider. It is a simple tool that works as a background service and does not require opening applications or using any other hardware.

This is a free tool that works on most Android devices. To use the tool, you must ensure your phone is connected to the Internet. The tool can record both incoming and outgoing calls.

The recordings are stored in a folder that you can access from your device and can be exported to MP3, OGG, WAV, and AIFF formats. You can mark your recordings with a star and save them to a folder you can access from your device.