Textual and visual app-based communication is standard everyday interaction. I argue that, as researchers, we have to be better equipped to include various ways of interacting digitally with participants in qualitative research interviews. In this paper, I do a methodological focused analysis of app-based textual interviews (n = 98) with young people selling illegal drugs online. I challenge the earlier skepticism towards interviewing through text, while also placing the interview in a new context of encrypted mobile phone applications. App-based textual interviews prove to be highly flexible and create a socially informal character of semi-structured interviews that interviewees perceive as safe. At the same time, the interviewer's position is decentered as the interviewee takes full control of the interview context behind the screen. App-based textual interviews proved highly useful when interacting with a younger generation, also on a sensitive topic like illegal drugs. It also introduces several ethical dilemmas for discussion.