Graphene has an app in the Accrescent app store
Discussion

But yeah
if the need is just for voice to text input for the phone, this or sayboard
or gboard with networking disabled
Yeah I've used this
I thought they meant a site that would do the transcribing for them
Rather than personally having to speak the whole thing into text
Which I think you could do with this
although I had problems with it just doing half a sentence and then getting confused