The web version currently has replay speed fixed at 0.5x, 1.0x and 1.5x, but the android app has a full slider with adjust of 0.5, 0.75, 1.0, 1.25, 1.5x.
Can we please have the same adjustment on the web page, or better as an even more adjustable in say 0.1 increments like 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 so we can fine adjust.
Personally I find the 0.5 to be painful to listen to (too slow - unless really trying to hear a tone difference), and as a learner probably never want to speak faster than standard so I am not sure what 1.5 would be used for.
But I do find it useful to slow down especially as I am trying to bridge from elementary to intermediate where the sentences are much longer and I need more time to think, but the web version does on have anything between 0.5 and 1.0x, so it is currently too slow or too fast for me.
I would suggest you implement the same play speed adjustment and apply its speed to all dialogue and all single sentence replays, but not for the vocabulary single word replays as they are already at a good speed for learning.