I was looking to create a custom activity indicator, but adding additional time to a project was not possible. I found this cool project SpinKit-ObjC that provides ready made indicators.
Below is a demo of a few of them I checked out.
UIView *myView = [[UIView alloc] initWithFrame:CGRectMake(105, 100, 100, 100)];
RTSpinKitView *indicator = [[RTSpinKitView alloc] initWithStyle:RTSpinKitViewStyleChasingDots color:[UIColor whiteColor]];