Functionality like iOS's keyboard shortcut functionality
There are good apps that allow you to set up text expansion with a nice GUI. This is the one I have used and liked:
Dash Expander
Mac App Store Link
Dash Expander handles text expansion very well. I have used it and it works well. The free version:

&quot;...will nag and annoy you every now and then, in order to purchase.&quot;

I haven't found these to be that obtrusive. However, as of writing the full version is just $1.99. This also has the ability to set variables. For example, you can set up a boiler-plate thank you note, and just set variables in there that you quickly go through and change to personalize for the recipient.