Yes for sure. I had been using DAF pro app you mentioned for years, occasionally - not all the time. The other day I just bought the Speak for less fluency device which has been good for me. As you said it is not for everyone, but for me it does help, especially when im nervous. I am quite shocked how none of my speech therapists introduced it to me and I found it myself as an adult - be it the only thing that helps my speech (alongside acceptance and openness about my stutter helping a lot). strange how it is not known by most people?!