This is one of the easier root methods I have seen. Since the Cricket version of the Samsung Galaxy S4 will be using a Qualcomm chip, we should have no issues using it. In the video I use an AT&T S4.
Credit - djrbliss @ XDA
Drivers: Support - AT&T Cell Phones SGH-I337 | Samsung Cell Phones
XDA Thread with Download (thank the dev): [ROOT] Root Samsung Galaxy S4 with Motochopper - xda-developers
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