This keyboard shortcuts are the more useful:

Cmd+Alt+º Set a breakpoint
Cmd+Ctrl+Up/Down Change from .h to .m files and viceversa
Cmd+Ctrl+Left Return to previous document
Cmd+Ctrl+Right Return tho the next open document
Cmd+Enter Normal view
Cmd+Alt+Enter Assistant view
Cmd+1 Show Project Navigator
Cmd+0 Hide Project Navigator
Cmd+Alt+0 Hide/Show utilities
Cmd+Shift+y Hide/Show output
Cmd+Alt+y Continue debug
F6 Step to step debug
Cmd+f Find
Cmd+Shift+f Find text in all project
Cmd+e Use selection to find
Cmd+g Find next
Cmd+b Build
Cmd+r Run
Cmd+u Unit test
Cmd+’ Go to the next Error or Warning
Cmd+. Stop debug o see autocomplete
Esc See autocomplete
Cmd+Shift+o Open Quickly (Amazing!!!!!!!!)
Ctrl+6 Find method in the open file
fn+Alt+Up/Down Paginate moving the cursor
Cmd+Shift+7 Commant out selected lines
Cmd+Ctrl+j Jump to the definition of the selected symbol
Cmd+Ctrl+e Edit all occurrences below cursor all at once
Cmd+Shift+2 Open Organizer
Cmd+Alt+j Filter in navegador
Cmd+Alt+l Filter in library