Using an iPad as my Ebook

The search never ended to find the perfect ebook. Refer to this Hacker News thread

Ask HN: What E-Reader devices do you recommend?

I just saw the Kindle Scribe launch, but it still does not satisfy my needed features, albeit being my near-perfect version of Kindle. First and foremost, I would want to have a good e-reader with multiple e-book store vendors (no lock-ins), with additional features like the following:

My good-to-haves

• USB-C
• Decently large screen
• Pen support
• Decently long-lasting battery (more than 20 hours of reading time is enough for me)
• Decent Note-taking & highlighting features
• Decent software (Onyx fails here)
• Pretty easy way to send & open files on the device (for PDFs, PPTXs, EPUBs)

Recent Kindle versions check almost all checkboxes here, but I would love to see multiple e-book vendors. I also read many Korean books, and the Kindle store lacks Korean titles. Knowing that Amazon loses money for each Kindle sale to boost their Kindle store revenue, it seems unlikely that Kindle will open up external app support.