I have been doing a collection of tools relevant to a life as a developer on .NET, but having recently swiched to Mac - here is the same (current) list as an XCode developer.
- XCode 7.3
- Charles WebProxy (www.charlesproxy.com) for debugging communication
- PostMan (www.getpostman.com) for crafting JSON queries ad-hoc
- SourceTree (www.sourcetreeapp.com by Atlassian (no better alternative for the time being even I am never a fan of SourceTree)
Quite a short list, but life in Mac world is simple (remember: simple != easy)