Working with code
Command + [ : Shift line left
Command + ] : Shift line right
Command + / : Toggle comment
Command + Control + J : Jump to definition
Command + Shift + F : Find in project
Comamnd + F : Find in file
Navigating Xcode
Command + Shift + Y : Toggle Debug Console pane
Command + 0 (zero) : Toggle Navigator pane
Command + Option + 0 : Toggle Inspector pane
Command + Option + Enter : Toggle Preview canvas
Command + Shift + L : Open Object Library
Command + Control + Left/Right Arrow : Go back / forward
Running your project
Command + R : Run project
Command + . (dot) : Stop project
Command + B : Build project
Command + Shift + K : Clean project