As earnings continue to roll in, Jim Cramer tells TheStreet's Brittany Umar what key reports he'll be watching. With Twitter's report on the horizon, Cramer explains the struggles the company is facing and why he's not expecting it to post a great quarter. Still, he reveals the level at which he would be a buyer. Plus, after a good quarter from FedEx, Cramer explains what to expect from UPS' report. He breaks down how to play the stock heading into the results and why he believes it is a great, safe stock to put away. Lastly, although he likes Whole Foods' long-term story, Cramer reveals why he's concerned about the stock.