How to launch a process from my app?

Hi!
I have a non-GUI app. And I need it to launch another application. That "another application" is mine too, so I can change a code of it.
Because first app is non-GUI it has no singletone of UIApplication and no custom URL can be sent.

system и execv commands don't execute a code passed to them and return -1 in a code like this:

Code:

NSString *path = [[NSString alloc] initWithString:@"killall SpringBoard"];
int res = system([path UTF8String]);
NSLog(@"res = %d", res);

Any ideas how to solve such a problem?

PS I don't want all of this to be appStore approvable! This is for jailbroken devices