I’m new to iOS app development and very curious with a lot of things. I was wondering if there’s anything that you find cool about Apple’s Human Interface Guideline (HIG) that you want to share! :))
For me, I find it cool that they take into consideration avoiding using color combinations as the only way to distinguish between two states or values. Many colorblind people find it difficult to distinguish blue from orange; other problematic combinations are red and green, red and black, and either red or green combined with gray.
For example, instead of using red and green circles to indicate offline and online, you could use a red square and a green circle.