I am looking for a voice recorder for Android that is not visible when recording (= not visible in the nodification bar, in the lock screen, and notification LED) and records voice in a decently compressed format (mp3, 3gp, etc. even compressed lossless like FLAC).
The native voice recorder application leaves marks pretty much anywhere it can (notification bar, lock screen, etc.). Smart Voice Recorder is almost perfect but save recordings as .WAV.
If possible, free and works with android 4.4.2.