- A quick video showing how to unblock blocked calls and private numbers with TrapCall. Once you've activated TrapCall your phone just reject any blocked calls and TrapCall will take over. Within a few seconds you'll get a call back with the blocked number unmasked — the caller will have no idea that you can see their number! TrapCall works on ANY cell phone for AT&T, Verizon, Spritn and T-Mobile. Always know who's REALLY calling with TrapCall.net!