Voice recorder for Android with marker support

Question

I'm looking for a voice recorder to be used on one of my Android devices.

Requirements (must-have)

• works on Android 6+
• lets me set the desired recording quality (a discussion must not be recorded HiFi – but a music session probably should)
• lets me set markers while recording (think of chapters in an eBook, or a topic switch in a meeting). Playback being capable to "jump to" markers.
• must be free
• must be privacy-friendly (as much as possible; in the best case, it will only require permissions to access the mike and the storage)
• low battery use (so I can have it running multiple hours without a break)
• support "long recording sessions" (it's OK if it starts a new file e.g. every hour); a 6h limit would be OK
• Recording in background (even when display is off)
• playback capabilities (to listen into my recordings)
• should be simple and easy to use (so no "overblown" GUI)
• "small and handsome" (.apk shouldn't be tens of megabytes in size)

Nice-to-Have

• FOSS (free as in "free speech" and as in "free beer")
• availability on F-Droid
• visual "gain control" (so I can e.g. see whether the speaker will be heard in the recording)
• tagging of recordings (e.g. "speeches", "meetings", "business", "personal" …)
• simple edit functionality (to e.g. cut off from the start or the end of an recording, or to split a file)
• date-and-time stamping (if that's possible, e.g. via Metadata). Playback being capable to "jump to" timestamps.
• option to "skip silence" (i.e. only record if there's sound)
• also works on Kitkat (yes, I have some older devices which could serve as "dedicated voice recorder")
• still being actively maintained would be appreciated

Definitely NOT needed/wanted

• cloud storage (Dropbox, GDrive, whatever)
• tons of trackers and ad modules
• unrelated "Gimmicks"

I've already checked related questions, and they do not match my needs:

• Voice recorder for Android: None of my requirements, but only "should be invisible while running" – which again isn't one of my requirements
• Specialized audio recorder for Android: Meets my requirements on "low battery use" and "long recording sessions" (and one answer also covers the recording quality) – but not the others
• Android voice recorder that will allow me to save to dropbox: Contradicts with my requirements
• Voice recording while taking note: Not covering my requirements (except for time stamping)

Answer 1

From what I can see the app Recordense Voice Recorder meets all of your requirements (except battery usage which I don't know, but with the screen off I doubt it will suck much battery.)

Even let's you add tags from the lock screen notification directly.

Has a free version with some limitations (the worst of which is only 3 tags per recording https://play.google.com/store/apps/details?id=com.ls.iris.apps.recorder.light (the pro version is only $3.35)