This is a huge tangent, but I cannot resist asking: which of the mobile OSes is best at allowing the user to customize text size? Suppose for example, the user is old enough to need glasses to read small type, but would prefer not to have to put on his glasses to use his smartphone. Let's leave the mobile browser out of this (because it is more complicated) and focus on apps for calendaring, plain-text email, plain-text notekeeping and texting.

A lot of it seems to depend on decisions by app developers. Unless I am very much mistaken, most iOS apps written by Apple do not allow the user to change the size of the text, but at least one iPad app (PlainText, which is similar to Notes) give the user a choice between at least 2 text sizes.