Good day!
Such a question, as I understand it, is possible in the android to somehow display something over standard applications (I'm interested in the camera). ( Work over standard Android applications )
Actually a subject, please tell me what you need to implement this? Something I did not think at all how to approach this topic.
PS: if there are knowledgeable people, I would be very grateful for the answer on a similar question for Ios.
Thank!