No, it can’t!
Either mobile internet (data plan: 3G, GPRS, EDGE, UMTS, WCDMA, HSDPA, HSUPA, HSPA, HSPA+, LTE) or Wi-Fi Internet connection is required.
GPS is able to identify location of the phone, but it cannot send received coordinates to the server. While it is the server which shows you the location of the target phone. Thus, Internet connection is needed.
However, we are working on the Premium version of the app with a possibility to request phone location via SMS. Stay tuned 🙂