Over the course of this book, you'll learn how to create an effective UI, but before we get stuck into this, it's helpful to have the end goal in sight.
A successful Android UI should be as follows:
Clear...
Your UI is how your app communicates with your users. Make sure it's clear what your app is trying to say!
If the user can't glance at every single screen within your app and immediately know what the screen's asking them to do, then your UI isn't clear enough.
....But not too clear!
How can a user interface be too clear?
Imagine a screen that feels the need to explain each and every UI element. Sure, this kind of UI would be clear, but would you persevere with such an app? Or would you look for an alternative app, one that isn't crammed full of unnecessary and, most likely, irritating text, such as Tap the Submit Results button to submit your results?
An effective UI strikes a balance between being clear and concise. If you design your UI well, the user will immediately know that the + icon in your music-playing app means add new track to playlist, without you cluttering up your UI with additional text.
Responsive
No matter how great your app's content, if the UI is laggy and prone to freezing, no one is going to want to use it.
An effective UI is responsive, smooth, and plays out like a conversation between the user and your application. For example, imagine you've just downloaded a new app and your first task is to create a new account. You fill in a form and tap Submit. Then, suddenly you're taken to an entirely new section of the app with no explanation of what's happened. Have you just created an account? Are you already logged into your new account? What's going on?
In this scenario, an effective UI would respond to you tapping the Submit button even if it's just a simple Thank you for registering your details - you're now logged into your account! popup.
Easy on the eye
In an ideal world, it wouldn't matter how attractive your UI is (or isn't). After all, if your content is good, what does it matter if your buttons aren't perfectly aligned? Or if your images aren't quite as high-definition as they could be?
The simple truth is that it does matter. A lot.
It's not enough for your UI to be clear, consistent, and responsive—it has to look nice, too.
It's also worth noting that creating an appealing, professional-looking UI may mean forgoing your own tastes and sticking with the safe option. Maybe you have a fondness for neon colors and have always thought that orange and green is a criminally underrated color combination, but remember that you're trying to attract as wide an audience as possible; is this aesthetic really going to appeal to the masses?