Let's start preparing to interview people over the phone.
First we need to find an app that will record both ends of a conversation. Voicemail is a great way to test if the app is working.
Remember to be follow the laws in your region and the regions you record in.
PRODUCTION NOTES
I recorded the narration to this episode directly into the mic of a Samsung Galaxy Note 4.
I recorded test one into my Note 4 by using it as a normal phone.
For test two I recorded the phone call using a headset with a built-in microphone (Bose QuietComort 25)
I recorded and edited using the Auphonic Edit App.
I uploaded the edited recording as a mono WAV file to Auphonic.com to normalize the sound at -19LUFS. I did not make any other treatment to the sound. No levelling or noise reduction. I want you to hear all the faults and positives from both tests.
I uploaded the resulting WAV file to Anchor.fm to host the file and added the music from their free music stock.
Anchor automatically converts the WAV file into a 128kbps .m4a file (I'd prefer a 96kbps .mp3, but I can't change that).