除了Kindle，iOS上竟然找不到一个像样的MOBI电子书阅读器，why？是因为这种格式不流行吗？

看来是MOBI格式是被Amazon收购并废弃了。

Mobipocket has been owned by Amazon since 2005. Support for the MOBI format has been discontinued since 2011.

https://www.lifewire.com/what-is-a-mobi-file-2621997

没想到这回MOBI成了proprietary，而EPUB则是开放格式。（本以为MOBI是开放格式，EPUB是苹果是私有格式。）

EPUB is widely used on software readers such as Google Play Books on Android and Apple Books on iOS and macOS, but not by Amazon Kindle e-readers.

https://en.wikipedia.org/wiki/EPUB#Adoption

原来手机电子书阅读器市场就这么3个主要竞争者：Apple iBooks, Google Play Books & Amazon Kindle. 太可怕了。