We know that faith comes by hearing. And, making the Gospel available to people who live in hard-to-access places is a great challenge, so, this evangelistic tool is aimed at groups of oral tradition, non-literate or with difficulties in reading and/or understanding a written message.
It is known that a large part of the Amazon population, even in the interior, has access to devices compatible with reading SD-Cards, and it is common to use these media even where there is no cell phone/internet signal available. Therefore, this evangelistic tool becomes very useful for missionaries to reach the populations in isolated areas in the Amazon window.