A practical guide to app design principles: tips and best-designed apps

As a developer, there are some basic rules you should keep in mind to create attractive and compelling apps. On its website, Android gives developers some principles and guidelines in order to help them build their apps. These design principles were developed by and for the Android User Experience Team to keep users' best interests in mind. If you are a developer, you’d better apply your own creativity and design ideas as well as Google’s following advice when creating an app:

The basis of app design is to keep it simple. You can create very complex and comprehensive applications, but they have to be easy and instinctive to use for the people. Users don’t want to spend ten minutes looking for the pause button on a music player. Create a clear, fluid and useful design, but also appealing to the eye; don’t forget Material Design, Android’s guide for visual, motion, and interaction design across platforms and devices. Remember that Material Design’s goal is to provide a simpler, more minimalist, fluid and natural look and an intuitive user experience on a responsive interface. In order to do so, Android provides developers all the resources they need to create adapted apps following these design guidelines. To use material design in your Android apps, simply follow the guidelines defined in Google’s website and use the new components and functionality available in Android 5.0 (API level 21) and above. Android provides the following elements for you to build material design apps: a new theme, new widgets for complex views and new APIs for custom shadows and animations.
Your apps should captivate the users. Find new ways to surprise and delight them. A beautiful surface, a carefully-placed animation, or a well-timed sound effect is a joy to experience. Subtle effects contribute to a feeling of effortlessness and a sense that a powerful force is at hand.
Users love to add a personal touch to their apps, so don’t forget to include fun, optional customization.
When you design an app, it’s essential to know your audience, so always try to know and understand users' preferences. It’s better to place previous choices within easy reach than asking them to make the same choices over and over. Take your best guess and act rather than asking first, but always let your users have the final say.
Keep it simple and brief. Use short sentences with simple words.
A picture is worth a thousand words: when possible, use pictures to explain ideas.
People get overwhelmed when they see too much at once, so just show them what they need when they need it, hide options that aren't essential at the moment, etc.
Make places in your app look different and use transitions to show relationships among screens. Provide feedback on tasks in progress.
Save your users’ creations and let them access it from anywhere. Remember settings, personal touches, and creations across phones, tablets, and computers.
Users must feel smart while using your app: make your app easier to learn by leveraging visual patterns from other Android apps. For example, the swipe gesture may be a good navigational shortcut. If something goes wrong, give clear recovery instructions and be gentle in how you prompt people to make corrections.
Make important things fast: not all actions are equal, so decide what's most important in your app and make it easy to find and fast to use, like the pause button in a music player.

Other helpful tips

Each system has its own visual guidelines, but here’s a bunch of general tips that will work for any developer, any app and any platform:

Grids are the basis of mobile app design, so use them to guide you. The moment a dot, a word or a line is placed onto a canvas/monitor/screen, you have defined your margins and padding. That will define the space you have to work with.
Colour creates hierarchy: colour associations are culturally based so be careful with red and green call to action buttons, for example. Play with different shades to create hierarchy, like a black button, then a dark grey one, and finally a light grey one. It’s also important to try not to make the button colours the same colour as the site or app, because it will fade away.
Keep your visual elements consistent throughout: if one button is of one particular colour, then all the buttons of the same category should be the same colour. Also maintain this uniformity on all the screens: if one screen has 20px padding on all side, all screens must have the same proportions. Of course, you have to keep your text styles consistent throughout too, and choosing the right fonts is crucial. For example, Arial, Avenir, Roboto, or Helvetica are good choices, as they are clean and easy to read.
The trend nowadays is to move toward a more flat design.
Create a good logo according to your product.
The page title: screen titles on websites are great to remind the users where they are when they have a bunch of open tabs and don't recall the content.
Make interesting apps with a quick and efficient response to the users’ interactions. If they have to wait, let them know the app is working, so try to always respond to user actions (swipe, tap, click) with an animation or something else, giving some feedback that they have been heard.
If you don’t know which layout is the best for a particular problem, visit design libraries.

The most beautifully designed apps of 2014

According to lists published in December 2014, these are some of the most beautifully designed apps of 2014 for mobile, desktop, and the web. So if you are a developer, you know: go take a look!