over the years I tested MANY dedicated audio players[1]. And here is the thing: I'm still using an Apple iPod Nano 7g for music and audio books (m4b), because in my opinion there is nothing that comes close in usability and flexibility.
Here is why:
Music, Audiobooks, Podcasts - all supported
Tiny size - although not mandatory I hate bulky phones in my pocket
Battery life - Can listen for days without running out of battery
Usability - Greate UI Design and Earphone remote support[2]
Bluetooth 4.0 - already supported
The only optimizations I could find so far would be: Interchangeable storage - if the internal flash dies, the device is broken forever
Replaceable battery - it's hard to repair
Audio formats - flac support would be nice
Wireless sync - Not having to copy files via cable would be nice to have
The iPod Nano 7g is from 2012. I've seen many people designing custom PCBs and releasing Kickstarter projects for custom audio players[5] or game handhelds[6]. I know Rockbox (which is great, but its lacks support for Wifi and Bluetooth AFAIK and just does not compete with the UX of iPod's audio book features in my opinion) and iPod Linux. 10 years ago someone even reverse engineered the iPod Nano 6g display[3].Although I'm not skilled enough in PCB-Design, after some research I found the Lilygo T-Display S3 Pro[4] based on ESP32 S3, which would be the size, but lacks audio and OS. There is also the Mango PI CyberPad[7], which looked interesting, but maybe is already too clunky.
Programming wise, LVGL[8] may be a good framework to develop a modern and efficient UI - at least it looks promising.
So, why is nobody interested in recreating an iPod nano like device? It should be doable with modern tech, but Phones have completely taken over the market...
1: https://www.reddit.com/r/audiobooks/comments/14ue4un/comment...
2: https://github.com/advplyr/audiobookshelf-app/issues/847
3: https://www.youtube.com/watch?v=7TedIzmguP0
4: https://www.lilygo.cc/products/t-display-s3-pro
5: https://www.youtube.com/watch?v=1C597AkhGtw