iPhone can't execute "SBSLaunchApplicationWithIdentifier"

I want to implement a lockscreen tweak for the iPhone. On the lockscreen, I added a button which can unlock the screen and open the phone app. The code of this button action is:

[self unlockWithSound:YES];
int (*openApp)(CFStringRef, Boolean);
void* sbServices = dlopen("/System/Library/PrivateFrameworks/SpringBoardServices.framework/SpringBoardServices", RTLD_LAZY);
openApp= (int(*)(CFStringRef, Boolean))dlsym(sbServices,"SBSLaunchApplicationWithIdentifier");
openApp(CFSTR("com.apple.mobilephone"), FALSE);
dlclose(sbServices);

But when I tap this button to execute this code, iOS crashes and reboots in several seconds. My iPhone is running iOS 6, regularly jailbroken.

I saw this in the syslog file when I executed the code in background thread:

Entitlement com.apple.springboard.launchapplications required to use kern_return_t    _SBXXLaunchApplication(mach_port_t, char *, sbs_url_string_t, sbs_property_list_data_t, mach_msg_type_number_t, sbs_property_list_data_t, mach_msg_type_number_t, SBSApplicationLaunchFlags, SBSApplicationLaunchError *, audit_token_t)

and in main thread:

Oct 31 11:11:40 Kevin-Yes-iPhone lockdownd[41]: 2fe93000 _receive_message: walk away - non-SSL 1
Oct 31 11:12:13 Kevin-Yes-iPhone profiled[163]: (Note ) profiled: Idled. 
Oct 31 11:12:13 Kevin-Yes-iPhone profiled[163]: (Note ) profiled: Service stopping.
Oct 31 11:12:15 Kevin-Yes-iPhone securityd[363]: MS:Notice: Installing: (null) [securityd] (793.00)
Oct 31 11:12:15 Kevin-Yes-iPhone afcd[367]: Max open files: 125
Oct 31 11:12:17 Kevin-Yes-iPhone afcd[368]: Max open files: 125
Oct 31 11:12:33 Kevin-Yes-iPhone securityd[369]: MS:Notice: Installing: (null) [securityd] (793.00)
Oct 31 11:12:37 Kevin-Yes-iPhone lockdownd[41]: 2fe93000 _receive_message: walk away - non-SSL 1
Oct 31 11:13:00 Kevin-Yes-iPhone securityd[371]: MS:Notice: Installing: (null) [securityd] (793.00)

My question is: why can't my tweak execute this code? I am using iosopendev as my developing tool, is it a problem with iosopendev?

Solution

Here is the best way to solve my problem:

%new(v@:@)
-(void)launch:(NSString *)bundle {
    Class SBApplicationController = objc_getClass("SBApplicationController");
    id appController = [SBApplicationController sharedInstance];

    NSArray *apps = [appController applicationsWithBundleIdentifier: bundle];
    if ([apps count] > 0) {
        //Wait .5 seconds.. then launch.
        [self performSelector:@selector(launchTheApp:) withObject:[apps objectAtIndex:0] afterDelay: 0.5];
    } else {
        id app = [appController applicationWithDisplayIdentifier: bundle];
        if (app) {
            //Wait .5 seconds.. then launch.
            [self performSelector:@selector(launchTheApp:) withObject:app afterDelay: 0.5];
        }
    }
}

%new(v@:@)
-(void)launchTheApp:(id)app {
    Class SBUIController = objc_getClass("SBUIController");
    id uiController = [SBUIController sharedInstance];
    if([uiController respondsToSelector:@selector(animateLaunchApplication:)]) {
        [uiController animateLaunchApplication:app animateDefaultImage:YES];
    } else {
        [uiController activateApplicationFromSwitcher:app];
    }
}

Note: activateApplicationFromSwitcher will work better then activateApplicationAnimated