Although using the app to call 'back' to the UK is not cheap, the app effectively drives a bus through Ofcom's telecoms rules that carriers must abide by in the UK, Infosecurity notes.
Previously, the only way of spoofing a caller ID from an iPhone was to install a software-driven PBX such as Asterisk and then route internet telephony calls via an international telecoms carrier - such as Itellas - prepared to offer a service with user-driven caller ID selection.
The app, which uses the Itellas service, is not just designed to spoof caller IDs, however, as SpoofPro says it can be used to record calls, as well as change the timbre, tone and frequency of the caller's voice.
So who would use this app?
According to the company, a private detective uses the app to call parties he is investigating and who would otherwise not answer his calls.
"I use it for pre-texting", said one private investigator (that the firm talked to that wished to remain nameless).
"It is by far the best tool I know of that allows me to trick bail jumpers into showing up somewhere at a certain time so I can catch them", he explained.
SpoofPro claims that its app is one of the highest rated spoofing apps in the Android market and is also available in the Cydia store for those users that have jailbroken iPhones.