Using an N86 as a daily with a custom firmware (r/https://tinyurl.com/ybeo438b**), Just about everything works... Maps ( Nokia maps & Google maps), Email with Profimail. I am also able to sync my contacts and calendar from hotmail/outlook with the native email client. few other apps i use are Joikuspot (hotspot), Escarpod (podcasting), and X-plore for file browser.**
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lastly If you're in the US and want to pick up an N86 make sure you find a RM-484-3 that supports AT&T/ Cricket 3G Bands.. cheers
How about something using Symbian Anna or Belle? These were basically very basic smartphones, small and lightweight, working fast, no ads, and with good battery:
https://www.gsmarena.com/results.php3?sOSes=5&sOSversions=5300,5400
I used Nokia 500.
Have you tried Albite reader? Or Foliant - the site is in Russian, use google translate? If you use nokia x2-00, then you can only run java apps, you can search for more on google "java ebook reader". Have fun!