Sentry BT250 Bluetooth Headphones w/ mic

https://www.amazon.com/Wireless-Rechargeable-Stereo-Earbuds-Bluetooth/dp/B015NFWDX8

F-Droid - free open source apps for Android

https://f-droid.org/en/

Audio Recorder from F-Droid

https://f-droid.org/en/packages/com.github.axet.audiorecorder/

Features:

Mute incoming call audio while recording

Variety of format encoding

ogg (default)

wav

flac

m4a

mp3

opus

X-plore Android file explorer

https://play.google.com/store/apps/details?id=com.lonelycatgames.Xplore&hl=en_US

Audacity

Amplify tool

Bass and Treble tool