Don’t keep your crocodile waiting — start designing some levels to feed him!

This is a blog post by iOS Tutorial Team member Barbara Reichart who is currently doing her PhD at TUM, where she teaches software engineering and iOS development. In her free time she develops games (Treeo Games). Her first published game is Tw!nkle. You can also follow her on Google+.

In this tutorial, you’ll learn how to make a level editor for the Cut the Rope clone that was previously covered on this site.

Using the level editor you can easily make new levels. All you have to do is drag and drop the ropes and pineapples to where you like them.

What is cool about this level editor is that it is build into the game, so players can create their own levels directly on their device.

Although a level editor can be incredibly fun for the end-user, it’s also pretty handy for the game developer to quickly assemble levels instead of hand-coding them.

An added benefit is that a level editor allows you to test-drive your game concepts. This can be especially important for physics games like Cut the Rope, as sometimes it can be hard to predict the behavior of the physics engine, but very easy to test those behaviors in real-time.

A level editor is a great way to increase the longevity and utility of your game by providing your players with the power to create their own levels — and even share their creations with other game fanatics.

In this tutorial, you will create a level editor for the Cut the Verlet game that was previously covered on this site. Didn’t catch the game creation tutorial the first time around? You can read about the game implementation in the tutorials below:

• How to Make a Game Like Cut the Rope – Part 1
• How to Make a Game Like Cut the Rope – Part 2

Keep reading!

How to Add Borders,Overlays and Animations To Videos in iOS

This is a blog post by iOS Tutorial Team member Abdul Azeem, senior software architect and co-founder at Datainvent Systems, a software development and IT services company.

The preceding AVFoundation tutorial in this series, How to Play, Record, and Edit Videos in iOS received some great response from readers. In fact, most readers wanted even more tips on advanced editing features that could add that extra touch of polish to their videos.

This follow-up AVFoundation tutorial is full of fresh new tricks to add some cool and professional effects to your videos.

The first AVFoundation tutorial showed you how to:

• Select and play a video from the media library.
• Record and save a video to the media library.
• Merge multiple videos together into a combined video, complete with a custom soundtrack!

This new AVFoundation tutorial will build upon that by teaching all you budding video editors how to add the following effects to your videos:

• Colored borders with custom sizes.
• Multiple overlays.
• Text for subtitles or captions.
• Tilt effects.
• Twinkle, rotate, and fade animation effects!

To get the most out of this tutorial, you will need to have some knowledge of the AVFoundation video rendering concepts described in the previous tutorial such as AVAsset and AVComposition. If you need to brush up on these topics, check out the previous tutorial before continuing. You could also refer to the Apple documentation for even more detailed information on the subject.

Ready? Lights, Camera… Action! :] Keep reading!

Learn how to make your app do stuff even when it is no longer active

This is a blog post by iOS Tutorial Team member Gustavo Ambrozio, a software engineer with over 20 years experience, including over three years of iOS experience. He is now a happy senior software engineer for PocketGems coding mobile games. You can also find him on Google+.

Beginning with iOS 4, you can design your apps to stay suspended in memory when users push the home button. Even though the app is in memory, its operations are paused until the user starts it again. Or are they?

Of course there are exceptions to this rule! In certain situations, the app can still run some operations in the background. This tutorial will teach you how and when to use (almost) all of these background operations.

There are important restrictions on the use of background operations. This is not a magic solution for getting “real” multitasking on iOS. Most apps will still get completely suspended when the user switches to another app. Your app is only allowed to keep running in the background in very specific cases — playing audio, getting location updates, downloading new issues for Newsstand apps, and handling VoIP calls.

If your app does not need to do any of these things, then you’re out of luck… with one exception: all apps get up to 10 minutes to finish whatever they were doing before the app is truly suspended.

So backgrounding may not be for you. But if it is, keep reading!

As you’ll soon learn, there are five basic background modes available to you in iOS. The project you’ll build in this tutorial is a simple tabbed application where each tab demonstrates the backgrounding abilities of one of the modes – from continuously playing audio to listening for incoming voice-over-IP connections.

Let’s get started!

Keep reading!