Speech Products and Devices?

Speech Products and Devices? Hi everyone, I’ve stammered all my life, as have my brother and my dad. When talking about stammering, we realised we’ve never really come across a physical aid designed to help develop our speech. I’m familiar with ‘SpeechEasy’ and similar devices that utilise the choral effect through delayed auditory feedback (DAF). I also haven’t been to a speech therapy session since before secondary school, so perhaps there are new tools being used that I just haven’t come across? Apart from DAF devices and apps, there doesn’t seem to be much else available online that can genuinely help improve speech development.