What are the ways to reduce bundle size on iOS?

Question

I have some images which are huge in size and my bundle size currently is 70 MB. I think Xcode already runs the assets through png crush.

Answer 1

• Do not use any text images with useless effects, use UILabels instead.
• Draw simple shapes and effects using CAShapeLayers instead of using images.
• Use JPEGs instead of PNGs where you don't need transparency. (Actually file size depends on the image content here)
• Use Save for Web option in PhotoShop or other tools to optimize PNG images.
• Use sprites combined together instead of separate images.
• Make sure you delete all unused resources.
• Do not localize common parts of the images, localize only the different parts. (think of a background image with a small flag at the bottom for each locale. use one single bg image and separate flag images. localize flag images only, not the entire bg images with the flags.)
• Use the same splash images for iOS7 and previous iOS versions. (You need to manually edit the JSON file in .xcassets)
• Try using a CDN to download assets on the first launch.

In addition to images keep those in mind too:

• Try replacing custom fonts with default system fonts if you don't need them really.
• Use MP3 audio files instead of WAV files. (or other compressed formats)
• Make sure you delete all unused 3rd party frameworks.

Answer 2

You can try converting the images to jpg (if they don't have any transparent regions). Also try using http://imageoptim.com/