To read a book on your phone is no biggy, you will find many apps that easily import and manage all the Epub's and Mobi's or Pdf's you like.
Seemingly for PC this is not as diverse, which made me install an app that can feel like it has possibly been decommissioned just by the look of their site alone.
Calibre is still very much up to date and through a quick scan of the search results, it is still the only genuinely full-featured Ebook reader and manager.
Since I used Reedsy to create a test Ebook and their interface is really nice for that, I still needed a quick way to preview it.
Aside from a quick preview method on the PC I wondered why the Epub version kept having rather crappy spacing issues.
For a moment I thought I recalled Edge being able to open Ebooks just by dragging them into the browser but guess I was mistaken.
In my Ebook reader results there was also the option for IceCream reader which I do remember using once but I know Calibre had more features and is basically open source.
With Calibre I am able to import thousands of books in one go and have them indexed easily. I can take one format - say a .mobi - and export that to Pdf or Epub as I need. I can also pull in a Word document and it will convert that to Epub also, and yes I have tested importing thousands of books since I used to download Epub dumps from torrents back when I was hoarding random digital assets.
The interface for the different bits can seem a little much but really all you need to do is stick to the basics, import, read and maybe for some reason you want to send someone a Pdf copy of one instead of an Ebook format then you can easily convert.
The rest of the features, don't use them if you don't need them then you won't get all hot and bothered.
I also like having Calibre as an option to preview exported files from Reedsy or as an alternative to my phone app for reading because if their is a layout issue like I notice happens especially with Epub when something contains images. Then at the very least, I can confirm this is an Epub issue, surprisingly the .mobi versions handle images like a boss.
Too bad .mobi is a Apple thing and the world went fuck that we want Epub.
Anyhow, Calibre is a useful tool to have on your PC if you do juggle quite a few Ebooks even just as a way to make a backup catalogue of the files on your phone.