If you ever tried to send an encrypted e-mail with GMail, you know how dispropostional hard it still is nowadays...
Even with things like GPG for Mail you have to understand how public- and private-keys work and everbody participating in the conversation has to know it as well!
Same is true for security standards like S/MIME, that should have made it simple for consumer software like e-mail clients to use encrypted or at leased signed e-mail communication.
Apple is at least coming to the conclusion that those things should be pushed forward and so iOS8 has better support for S/MIME built-in, you will be able to choose encryption and signing on a mail-by-mail basis.
Another thing that Apple does well is with their messaging system iMessage, which is built into all recent Apple operating systems on iOS and OSX.
The messaging service is supposed to be a secure communication channel under the premisis that you consider Apple to be a non diablic company...
They can, at any point, insert something into their proprietary systems that would make it possible for 3rd parties to read all communication, or maybe they alread have a backdoor builtin?
The proprietary of iMessage is also the biggest disadvantage, it's not interoperable which is kind of a no-go nowadays.
Same is true for the recently hyped messaging app Threema, which is rated pretty good in terms of security.
While it's available for iOS and Android (Windows Phone is currently under development), it's still not interoperable with Desktop-PC or OSX due to it's proprietary communication protocol.
A really good alternative to Apple and Threema is the OTR crypto protocol which builds on top of well established chat protocols like XMPP (Jabber) to encrpyt messages between two parties.
Unfortunately in the time of smartphones, handhelds, laptops and other internet enabled devices, this type of encryption has one serious drawback.
The messages can only be encrypted between the two parties initiating the encrypted communication, so messages sent from your laptop won't be readable on your smartphone and vice versa, communication get's scrambled, which leads to a horrible user experience.
The internet already has everything we need to enable secure and encrypted communication channels, it's just not simple!