// Button to save alpha using NSUserDefaults

    NSUserDefaults * alphadefaults = [NSUserDefaults standardUserDefaults];
    [alphadefaults setFloat:cross1.alpha floatForKey:@"CrossAlpha1"];
    [alphadefaults synchronize];

// Button to load alpha using NSUserDefaults

cross1.alpha = [[NSUserDefaults standardUserDefaults] floatForKey:@"Cross1Alpha"];