NSUserDefaults is kinda like git

Note that like all analogies, this is not a perfect one. I find it helps me think about it though. Also, don't try to draw conclusions about performance from this analogy :)

-[NSUserDefaults setObject:forKey:] is like...
<edit file to add key and value>
git add file
git commit
dispatch_after(some time, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    [[NSUserDefaults standardUserDefaults] synchronize]
});

-[NSUserDefaults objectForKey:] on 10.9 is like...
git pull --rebase
grep key file

-[NSUserDefaults objectForKey:] on iOS 7 is like...
grep key file

-[NSUserDefaults synchronize] is like...
if (git diff --staged != empty) {
	BOOL pushedSuccessfully = NO;
	do {
		pushedSuccessfully = git push
		git pull --rebase
	} while (!pushedSuccessfully)
} else {
	git pull --rebase
}

Terminating an app normally is like committing your work, pushing, and leaving

Terminating an app abnormally (memory pressure kill, crash, stop in Xcode) is like git reset --hard HEAD, and leaving