I do like your videos, but find they encourage you to be a passive listener, rather than practicing speaking - so I use your dialog and extension sections a lot. Otherwise I end up just thinking I know it but cannot say it.
Because of this I do value the sentence by sentence playback given in the dialog and extension sentences.
Unfortunately the playback of each sentence has no speed control, and it becomes to hard to learn/hear the tones
Could you please add speed control button that allows a slow version - at say 70% so that you can slow down in a similar way to the videos.
Could you also consider a record and playback button that allows you to self record the sentence and play your own voice back giving ability to play own voice and quickly compare with the lesson version.
Oftentimes I think I say it right but on self record and playback I find I have missed half the tones . Adding playback and comparison to lesson version within your webpage or app. would make learning and self testing so much faster, especially as you have such a wide range of sentences to self test on…