Nope. Too many security flaws and exploits on the older versions. Update to something newer or Amazon means a closed book to you. ;) Browser and "Cloud reader" might work, not sure.
Amazon, Apple, Google and even Microsoft are finally cracking on on outdated software that leaves people (and the ones they connect to) wide open to trouble.
Any iPhone older than a model 6 for example will effectively be a lovely paperweight by the end of the year as I understand things as they cannot be made safe enough for current needs.
This is one of the reasons you can pick up older iPads and iPhones dirt cheap almost everywhere you look. The reseller companies know they are or will soon be mostly useless but count on people seeing a bargain but not knowing the "why" of it and letting dollar signs blot out rationality.
Note: I have checked sites referenced and they appear safe but I make no promise or guarantee. Ads or content you don't like might be lurking so use entirely at your own risk. I have no connection, fiscal or otherwise, with any site referenced.