The negative reviews on Google Play should give you pause but to elaborate:
- This is US numbers only so if you're someplace else, stop here.
- The so-called deal is to use them to by-pass ringing and drop a message straight into that person's voicemail. Your caller-ID is used so there's that positive. And a 1 to 1 is in fact straight up and not some spam machine unless you want to sit and do this endless, one at a time.
- However, it's a taste. The app DOES have the ability to purchase and up-to-ten at once, which is a gateway to the larger app offered by the same company which is specifically designed to create campaigns that do give a spammer an automated tool to blast messages all over the place. DNC rules should apply here.
- The deluxe product lets you hit landlines and mobile phones, as well as spoofing your caller-id as per the website.
- I totally get why somebody trying to dial-for-dollars with a special offer on widgets to a set of people who sign up for a voice notification would love this app.

Sadly this is a spammer's dream and technology like this should be restricted with the voicemail and telcos being held accountable for abuse. I rate the app a one not because the tech is faulty, rather because of the company's lack of actually doing the right thing with respect to do not call lists. They could easily implement technology to deal with it as well as preventing spoofed caller-id.