/* myFunction exists under the loop function. */
/* This function will be invoked each time a new tweet comes with the tracked word. */
void myFunction (char * userName,char * tweetText)
/* Print out the phone userName and tweetTexton Terminal shield. */
Did the Twitter shield pops up a message states the it started tracking the keyword, Also do you have a good internet connection ? Cuz sometimes Twitter API misses a tweet due to weak internet connection. make sure that Twitter.trackKeyword(keyword) is sent to the application to track that certain keyword and please leave the Twitter shield opened until you are sure that the pop appeared.