Gecko

Gecko is a free, open-source time-travelling audio recorder for Android. It keeps a rolling in-memory buffer of microphone audio so you can save something that just happened, then optionally keep recording forward.

Features:

• Continuous listening into a ring buffer (foreground mic service)

• Save the last 1 / 5 / 30 minutes, 2 / 6 hours, or everything held

• Press-and-hold a duration chip to save history and keep recording

• Settings for RAM budget and sample rate (8 / 16 / 44.1 kHz)

• Exports WAV files to Music/Gecko via MediaStore

• Restarts listening after reboot if it was left on

• Multiple UI packs (Biolume, Sonar, Oxide, Volt)

Privacy:

• No ads, no analytics, no crash reporters

• Audio stays on-device; nothing is uploaded

• Microphone is used only while listening is enabled

Battery notes:

Defaults favour battery (8 kHz sample rate, power-saving mic mode, quiet notification). Raise sample rate in Settings when you need more fidelity.

Source: https://github.com/anantdark/Gecko

License: GPL-3.0-only