Swift and Xcode - How to Create Custom Tab Bar Icons

After a bit of research I resolved the issue, so thought I'd post here in case anyone else has a similar issue. In Photoshop I did the following:

1. Imported the image I wanted to use as the tab bar icon (its easier if you use a black and white image so that you don't have to remove colour).
2. Set the background to 'Transparent' rather than white.
3. Removed all white from the image so that it was just a black image with a transparent background.
4. Saved the image as a .png.
5. Resized the image to be a square with dimensions 75x75 pixels (and named imageName@3x.png), 50x50 pixels (and named imageName@2x.png), and 25x25 pixels (and named imageName.png)

In Xcode I did the following:

6. Dragged the images into Xcode and renamed the image group as icoImageName.
7. Selected the tab I wanted to set the image for in the storyboard in Xcode and set the 'Image' (under 'Bar Item' in the Inspector Pane) to icoImageName. Note that I did not set the 'Selected Image' under the 'Tab Bar Item' (leave this blank).

Done.

I hope this helps someone. Thanks to everyone for their help as well.

It sounds like you have everything set up properly in xCode. The problem IS the png file you are using.

Download this image, http://i.stack.imgur.com/zluev.png , and see if the problem persists.

According to an answer on UITabBarItem images just appear as a grey block:

The standard tabbar icons in iOS are rendered solely from the alpha channel. Colors are ignored completely. Instead of colors you can use different alpha values that lead to a different shade of gray (or blue if selected)

Make the background of your icons transparent.

Did you create the tab view in interface builder? If so, since you added the images as an asset they should show up in the 'Image' property of each tab button under the inspector sidebar. Also, I know you've already posted a ton of tutorials, but this one is pretty up to date and explains it thoroughly: http://codewithchris.com/ios-tab-bar-app/