This app was mentioned in 17 comments, with an average of 1.71 upvotes
Cogi. It's an interesting voice recorder app with a twist. (Go see the page). But I've never been in a situation where I would actually need to use it.
I use an app called Cogi, which has the same feature and more. So much more that it is quite a bloat now and I'm looking for leaner alternatives.
The way Cogi works is -
Can something like this be done in your app?
Ok, here is the app I said could do that pre-recording stuff i.e. always recording. Then when you press Record, it records from some time before that. So you can catch an event that happened before you pressed the Record button.
https://play.google.com/store/apps/details?id=com.cogi.mobile Cogi – Notes & Voice Recorder
We have gotten requests for including something like that as well, so may include something like that in this app (which is currently in Alpha Testing): Amazing Audio MP3 Recorder
Taking your motivation at face value - this seems like an awful fit for the use case you've described.
Suppose you want to refer back to a note you took sometime yesterday. then what? are you going to randomly speed through 720 minutes of audio filled with background and pocket noises? Suppose you want to make a summary of the day's instructions. Are you going to listen to 720 minutes on x2, fully engaged?
Not to mention what people mentioned about the dubious legality of constant recording where people might expect a right to privacy.
If you want a recording app, with the ability to capture and tag selected chunks, as well as take photos, I used to use Cogi
If you are looking for audio recorder apps which are continuously recording in the background - and then if you hear a sound bite that you want to record, you press a button, and the recording from 30 seconds ago (which will therefore capture that soundbite) will be saved to a file.
Then here is a list of such apps:
Cogi – Notes & Voice Recorder
Rewind: Reverse Voice Recorder
Echo: Time Travelling Recorder (saidit)
If you just want a recorder that can record fast, you could try our app:
If you keep proximity sensor feature on (Ear Detect) - you can just flip the phone face down to record.
Or if you want to record when screen is off - you could use the Power Controls feature - where you click 3 times on the Power button to Record/Stop. This will work even if screen was dark/locked.
And there are other was to record there as well.
We also have a full s[creen gesture based app - where you can just swipe up/down/left/right to Record/Pause/Stop/Play. This makes it record even without looking at the screen.
Well our audio recorder apps do not have an auto-split - however, for WAV recordings they do have a multi-part feature which splits them at the 4GB file size mark (this is because WAV standard enforces a 4GB file size limit) - so our app basically allows you to make unlimited sized WAV files - except they are saved as consecutive files of size 4GB. App has been tested recording 100+ hours continuous (OGG file takes up 2.4GB) - and 34+ hours on single battery charge on Samsung Galaxy Note 4.
Linkme: Amazing MP3 Recorder
You could in principle set up Tasker or Automation type app to not only trigger our app (which are Tasker compatible) - but also delete the older files.
A variation on what you ask is available on some android apps (unrelated to us) - which offer a feature where the app is recording - but only start saving last 10 minutes etc. and going forward once you click the Record button. The primary intent of such apps is to catch the sound of lightning, or some sound bite on live TV - which you you only realize 10 seconds later was important and needed to be recorded.
Some apps which do this are:
Cogi is my personal favourite.
If you are looking for audio recorder apps which are continuously recording in the background - and then if you hear a sound bite that you want to record, you press a button, and the recording from 30 seconds ago (which will therefore capture that soundbite) will be saved to a file.
Then here is a list of such apps:
Cogi – Notes & Voice Recorder
It's not quite in the same realm, but I love Cogi for notes in meetings.