A few months ago, Apple made some changes to its Developer Program so that it could allow everyone to test apps on iOS devices without paying for a subscription. A pleasant side effect of those changes is the fact that developers can now release open-source iOS apps outside the App Store. In theory, everyone can use and install those apps though there are some noteworthy restrictions and requirements.
What you will need
There are a fair few applications that can compile code and run it in your iOS device but for the purposes of this guide we are going to stick to Xcode. When Apple changed the Developer Program, it also updated Xcode to version 7 which is now entirely free. The bad news for some of you is that Xcode is only available on OS X. Windows users can also join in by running OS X in virtual machines but there is no way to run the program natively on Microsoft’s OS. As for the apps you can install, they need to be open-sourced because you will require their source code in order for this to work. The limitations are pretty severe but there is always jailbreaking if you want more control over your iPhone or iPad. This method will at least allow you to run apps like emulators without jailbreaking your device so I am sure some will find it endearing.
Setting up Xcode
After you download Xcode from the Mac App Store and install it, launch it to add your Apple ID. To do that, click on Xcode > Preferences and then on the plus (+) button in the bottom left corner of the Accounts tab. Note that if you were previously subscribed to Apple’s Developer Program, you may run into an issue with Xcode and you will need to create and enter a new Apple ID instead.
Grab the app’s source code
At this point you will need to find the source code of the app you want to install. For this example we will use GBA4iOS, an established emulator, as its code is readily available on GitHub. Open a Terminal window and run the following command:
sudo gem install cocoapods; git clone https://bitbucket.org/rileytestut/gba4ios.git; cd gba4ios; pod install
Allow the process to complete and then head back to Xcode. Click on File > Open, find the GBA4iOS folder and open it. Now you have an open Xcode project and you are almost ready.
Building and installing the app to your iOS device
Take your iOS device and plug it into your Mac. Then, go to Product > Destination and select your device. This will allow Xcode to use your iPhone, iPad or iPod touch as the build destination. Once you have done that, click on the project’s name on the left side of Xcode and enter a unique name in the “Bundle Identifier” field. The default format looks something like com.thebest.app.ever but you can actually enter whatever you want. You will see an error that reads “No provisioning profiles found” but just ignore it. Instead, make sure that your name is selected in the “Team” field and then click on the “Fix issue” button to continue.
For the final and most glorious step, all you have to do is click on the Play button at the top left corner of Xcode. Provided that everything went well during the entire process, Xcode will install and run the app in your iOS device. If you do see an error, it may mean that there is a problem in the source code or that you forgot something during the setup.