There is the only Answering Machine for Android that REALY TALKS to the line during a phone call. You can take incoming calls, record voice messages, enter tone dialing, and answer all of this with pre-recorded voice phrases or beeps using Java script program.

See detailed description on site: https://sites.google.com/view/answering-machine

The standard headset or a special adapter inserted into the headset audio jack is used. See the Headset Adapter section for instructions.

Since it is impossible to pick up the phone programmatically on Android, you need to set the mode to "Automatic off-hooking when using a headset." It is in almost all phones. If you do not have this mode, the Application will not be able to work correctly.

Application Updates have four levels:
Demo - Pre-built firmware examples are used.
Home - Classical Phone Answering Machine.
Professional - Built-in Java to Java Virtual Machine compiler is used or the JVM code is edited directly. For advanced users and programmers.
Expert - You can create your own or modify the built-in scripting programming language by editing the language syntax file (the current simplified version of the language is only 160 lines). For especially advanced users and programmers.

The language of the script program is simplified Java.

Unfortunately, on some phone models, the application may not work correctly. In this case, just uninstall the Application and accept my apologies for the inconvenience caused to you.

Thank you for using the Answering Machine Application.

Good luck!

Sincerely, Vladimir Yukhlin.