Our planet is covered in tiny squares filled with a curious arrangement of shapes that mean absolutely nothing to the naked eye. They are on posters, billboards, business cards, cereal boxes, and so much more. For the most part we ignore them, because there's no reason to interact with these little squares unless specifically told to. They are called QR Codes, and once you figure out how to fit them into your life they can become an incredibly useful tool.
QR Codes are not a new technology, in fact they have been around since 1994 and were originally used to track components during vehicle assembly. Today you can find tiny QR Codes on components for tons of different things, as many companies still use this tracking method during assembly. For those of us who aren't building a car, these little squares are used mostly for presenting links to websites and apps in a way that doesn't require manual input.
You can just scan the code, and the link will either send you to the desired location on the web or present you with tiny chunks of data for your phone to save. This could bee contact information stored in a vCard, payment information that links to your bank account, or the link to launch an Augmented Reality protocol depending on what app you are using to read the information.
There's no one specific app used to handle QR Codes, you can use whatever accomplishes your specific goals in the most efficient way. This could be Google's Goggles app, the Borderlands 2 Loot The World app that turns hunting down QR Codes into a game, or any of the dozens of QR Code apps in the Google Play Store. In most cases, if you need a specific QR Code app to accomplish a task, there will be instructions next to the code itself advising you to install the correct app. Otherwise, any reader will do. Once you have the app installed you just open the app and hold your camera over the code, the app will do the rest.
Reading QR Codes is the easy part, especially if all you're going is grabbing a free song from a random music provider or grabbing contact information for someone you've met on the street. The real fun comes in creating QR codes, and finding reasons to use them either on your phone or on your smartwatch to get things done in your day to day life. For example, you can easily use an app to embed your WiFi login information on a QR code and leave it next to your router for friends who come over and need to join your network. You can even get clever with your QR codes and set them to a fixed redirect link, and then change where the link points any time you want to provide new information on the same code.
The truly clever thing about QR codes is that they don't have to look like these bland, generic squares. For some, QR code manipulation is an art form, creating beautiful designs and color patterns within the code itself without disrupting the ability to be read by the same generic smartphone apps. This is possible because error correction is built into the protocol, meaning up to 30% of the square could be missing entirely and you could still scan the pattern and get the information you want. These kinds of codes require a little more skill to create, as well as a website like QRPixel if you aren't quite ready to build one by hand, but the end result is often worth it for the unique design you get out of it.
Ultimately you get exactly what you want out of QR Codes. These little squares are either a great visual way to send short bursts of information or a total waste of your time depending on how you use your phone. For the most part, these codes get used as a clever way to advertise to tech savvy users, but there's plenty that can be done to make them personally useful if you put the time in.