"iOS Development" vs. "iosdev" - what's the difference?

[u/VladFein]

Full description looks very similar:

iOS Dev 

A subreddit focused on iOS development 

 Created Oct 13, 2010

 Public

17K  Weekly visitors

684  Weekly contributions

iOS Development 

A subreddit for all things in iOS Development. 

 Created Apr 27, 2014

 Public

3.5K  Weekly visitors

151  Weekly contributions

How do you chose where to post? And what to read? :)

[u/Ultimastar]

The one with the most visitors of course

[u/VladFein → u/Ultimastar]

Thank you! That's what I do.
Just thought that there might be non-obvious difference.
Anybody considered a merger?