I have no idea what Whispersync is but Kobo works very well with Calibre or Grimmory. You can change the store URL to your own Calibre(-web) [1] or Grimmory. S

I have no idea what Whispersync is but Kobo works very well with Calibre or Grimmory. You can change the store URL to your own Calibre(-web) [1] or Grimmory. Some of the Kobo also support audio books. All of them have microUSB or USB-C to sync, some got Wi-Fi or Bluetooth as well. Mine even has a mic for some reason. There's a plethora of hacks for devices like the Kobo (reMarkable is another one). For example, see [4] [1] https://calibre-ebook.com https://calibre-ebook.com [2] https://grimmory.org https://grimmory.org [3] https://koreader.rocks https://koreader.rocks [4] https://github.com/RiccardoSilva42/Kobo-Hacks-Comp https://github.com/RiccardoSilva42/Kobo-Hacks-Comp