I've been using aText for quite some time, and it's been amazing. If you are typing a lot, I'm sure you would be able to optimize your work tremendously. You can have abbreviations for your closing email phrases, URLs, and whatever can come to your mind.
Also, I'd suggest to think of a trigger character and use it at the beginning of all abbreviations. That way you will avoid collisions. I'm using a comma. For example, these are some of my abbreviations:
You get the idea. Once you get used to the app, it will save you a lot of time and typing.