I have iPhone 6 plus and an Android Nexus 5. I installed iLostFinder and setup personal hotspot on my Nexus 5 and connect my iPhone 6 to the portable hotspot once to remember the hotspot. In case my iPhone is lost or stolen, I can enable the hotspot and walk around so that my iPhone can connect to my personal hotspot when I get close to it. In this way, the iPhone gets Internet even if no Mobile data or SIM card. Then I can use alarm sound and Find My iPhone to locate it!