looping through an NSMutableDictionary

A standard way would look like this

for(id key in myDict) {
    id value = [myDict objectForKey:key];
    [value doStuff];
}

you can use

[myDict enumerateKeysAndObjectsUsingBlock: ^(id key, id obj, BOOL *stop) {
    // do something with key and obj
}];

if your target OS supports blocks.