The Rand Paul campaign smartphone app is “the slickest download in the history of presidential campaigns.”
In addition to the typical uses of gathering data, advertising events and taking donations and surveys, the app provides the user with the ability generate memes on the Rand Memerator.
The most off-the-wall and entertaining part of the app is the Easter Egg Space Invaders-like game, which reportedly can be accessed “by opening the ‘About Rand Paul’ section then vigorously tapping the Rand logo at the top.”
The user must defend Rand’s torch of liberty logo (the spacecraft stand-in) by blasting incoming space debris in the form of the logos of his opponents, such as Donald Trump, Hillary Clinton and Jeb Bush, as well as objectionable things such as tax percentages and red tape.

On a more serious note, the app will also alert users to Senate votes in which Rand will shortly be participating, asking how he should vote on the bill in question. In this way, it is implied that supporters can make a difference in the Senate by interacting with the app.
Chris Plante at The Verge says the app promises to be “a vessel for real-time democracy.” At a minimum, it is the most cutting edge app in the race so far.