RogerVoice works via the Internet i.e. it uses your data plan, not your network’s voice calling ability. So it works like Skype and its many competitors. To put it simply, you won't have your minutes depleted using the app.
One minutes of calls with RogerVoice uses 0.67 Mb of data in average, which should be covered by your normal plan with your operator. It really depends on your general use of data.
However, each RogerVoice phone call comes with a cost, billed to RogerVoice by network carriers. These costs are not covered by your normal plan.
During the 1-month trial, we will cover these costs for you, for up to 2.00€ of credits (which amounts to anywhere between 10 minutes to 1 hours of calls, depending on your call destination).
When the 30 days or the 2.00 € are reached (whichever occurs first) you can subscribe if you'd like to continue using RogerVoice and support our ongoing developments. You can learn more on subscription on this link: https://rogervoice.com/pricing.html