Recordator is a lightweight, open-source inspired tool that prioritizes offline function. It does not ask for unnecessary permissions (no location, no contacts unless necessary). It attempts to use the standard Android MediaRecorder API; if that fails, it defaults to microphone recording.
On rooted Android devices (e.g., Magisk), apps can directly patch the audio HAL (Hardware Abstraction Layer) or use kernel modules to record two-way audio without cloud interaction. This is the most reliable offline method but voids warranties and poses security risks. offline call recorder app for android