Tweak.xm

@interface MyAwesomeSingletonPleaseDontNameMeThis: NSObject
+ (id)sharedInstance;
- (void)registerForNotifications;
@end

@implementation MyAwesomeSingletonPleaseDontNameMeThis
+ (id)sharedInstance {
	static id _sh;
	static dispatch_once_t onceToken;
	dispatch_once(&onceToken, ^{
			_sh = [[self alloc] init];
	});
	return _sh;
}

- (void)registerForNotifications {
	[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(_applicationDidBecomeActive:) name:UIApplicationDidBecomeActiveNotification object:nil];
}

- (void)_applicationDidBecomeActive:(NSNotification *)notification {
	// explode or whatever
}
@end

%ctor {
	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
	[[MyAwesomeSingletonPleaseDontNameMeThis sharedInstance] registerForNotifications];
	[pool drain];
}

@interface MyAwesomeSingletonPleaseDontNameMeThis: NSObject

That's an interesting naming scheme...