I'm in business for 4 years. During that time my responsibilities were: software design and development, staff training (newcomers), projects estimation, continuous integration setup, code quality assurance, development strategy elaboration, team coordination.
By now, I'm skilled at:
Objective-C 2.0, UIKit, OCUnit, OCMock, CoreLocation, AVFoundation, CoreFoundation, ALAssetsLibrary, CoreNetwork, ExternalAccessory, CoreGraphics, Bash, Gcov/Lcov, Xcode
command-line tools, CoreData, sqlite3, XCode profiling tools, SVN, Git, Mercurial,...