[windtrader]

What is the big deal about this app? You can do callerid spoofing all day long for 1.5 cents per minute.

Get a grandcentral or google voice account. set caller id to use inbound CID.

Get a VOIP DID account that allows you to set the callerid. Have this number set to forward to your GV number.
Define DID number in Google voice as a phone.

Call your DID, it forwards to GV which recognizes it as a phone on account. Select option to make outbound call. Call is made and uses the spoofed callerid set in the DID.