jailbreak - Theos tweak: helloworld alert box did not show up -

i followed http://brandontreb.com/beginning-jailbroken-ios-development-building-and-deployment make tweak. every thing seems fine , make package install successfull,
when iphone respring, "helloworld" box did not show up, done 1 knows how solve this?

my xcode 4.6 , sdk5.1 installed
iphone ios6.1.2

i set those

export theos=/opt/theos/ export sdkversion=5.1 export theos_device_ip=192.168.1.101 

this makefile

export archs=armv7 export target=iphone:5.1 include $(theos)/makefiles/common.mk helloworld_frameworks = uikit tweak_name = helloworld helloworld_files = tweak.xm include $(theos)/makefiles/tweak.mk 

and tweak.xm

#import <springboard/springboard.h>  %hook springboard  -(void)applicationdidfinishlaunching:(id)application { %orig;  uialertview *alert = [[uialertview alloc] initwithtitle:@"welcome"     message:@"hello world"     delegate:nil     cancelbuttontitle:@"123"     otherbuttontitles:nil];     [alert show];     [alert release]; }  %end 

i figure out, *.plist should be
{ filter = { bundles = ( "com.apple.springboard" ); }; }

thanks @h2co3, find comment somewhere else
after done helloworld tweak.
hook fopen using mshookfunction

and meet linking error

making tweak hw...  preprocessing tweak.xm...  compiling tweak.xm...  linking tweak hw... undefined symbols architecture armv7:   "_mshookfunction", referenced from:       global constructors keyed tweak.xm.mmin tweak.xm.51941273.o ld: symbol(s) not found architecture armv7 collect2: ld returned 1 exit status make[2]: *** [.theos/obj/hw.dylib.ba964c90.unsigned] error 1 make[1]: *** [internal-library-all_] error 2 make: *** [hw.all.tweak.variables] error 2 

this tweak.xm

#import "substrate.h"  static file * (*s_orig_fopen) ( const char * filename, const char * mode ); static file * my_fopen ( const char * filename, const char * mode ){     return s_orig_fopen(filename, mode); }  static void entry(void)  __attribute__ ((constructor)); static void entry(void) {     mshookfunction(fopen, my_fopen, &s_orig_fopen); }