Your iPhone or iPad will become a lot less useful when they don’t get the latest version of iOS.  This is because a lot of times apps have minimum iOS requirements for their new versions.  So for example my 2010 vintage 4th generation iPod Touch can’t get the latest Skype app because it requires iOS 8 and I can’t upgrade it past iOS 6.  The biggest upgrades subsequent iOS devices are getting is the (often) doubling of their RAM.  For example the 4th generation iPod touch had 256 MB of RAM where the 5th generation one had 512 MB.  Similar RAM upgrades are present in the iPhone and iPad line as well.

Newer versions of iOS often require more RAM and this means that some old devices (particularly when RAM has doubled twice after two cycles) will be dropped off.  So if you are planning on buying an iOS device, my advice would be look at how much RAM it has relative to the other iOS devices on the market.  For example, the iPad Air 2 has 2 GB of RAM verses the iPad Air’s 1 GB so I’d say the iPad Air is much more future proof.  Same with the iPhone 6s which has twice as much RAM as the 6.

SHIFT-Enter – Gives you a line feed as opposed to Enter which gives a carriage return.  This is useful when you want a new line on a bulleted list (without it adding another bullet) or beginning a new line without ending a paragraph.  A rough HTML analogue would be Enter=<p> where SHIFT-Enter=<br>

CTRL-ALT-PrintScreen – takes a screen shot of just that particular application.  Great for browser screenshots.  As a bonus you can now paste copied screenshots directly into a GMail message.

SHIFT-CTRL-V – pastes your text with formatting removed.  This is particularly useful when copying text from web pages into e-mails where you don’t want to preempt the existing formatting.  Unfortunately this shortcut doesn’t work in a lot of Microsoft programs.

Any letter inside of a folder – click inside of a folder and type any letter and the file starting with that letter will get selected

SHIFT-CTRL-T (in browser) – brings back tab you just closed