Anyone who sends out Gmail messages containing the same body text over and over again knows how taxing that can be. Fortunately, there's a great feature in Labs called Canned Responses to help combat this issue by offering the ability to have pre-built responses directly within the compose window.
Let's say, for example, you're out of town and won't be able to respond to most email in a timely manner, but don't want to set an away notice so everyone gets the same response. In that case, you could have several different canned responses ready to go for different purposes. If a client or partner emails, then you could have an appropriate, professional message ready to go. Similarly, if your mother, friend, or other close person emails, you could have a response ready for that circumstance, too.
While canned responses are incredibly useful, there is one pretty big shortcoming: the feature is not available on mobile. In the aforementioned scenario, you're far more likely to see the emails on your mobile before your laptop, so why wait to send the reply? Fortunately, thanks to a new app called Gmail Canned Responses, you no longer have to.
In itself, the app is very basic: once installed it uses OAuth to authenticate and connect to your Gmail. From there, it lists all of your canned responses; a simple tap will copy said response. After that, you're only a paste away from sending your pre-made message, right from your mobile.
This app is incredibly useful for anyone who uses canned responses often, and, best of all, is completely free. Hit the widget to grab it.