and found another interesting article on the topic of reflective practice and assessment_ not specifically about spoken language but I believe it is applicable to it as well. 

The article is Learning through Reflection: Student Self-Assessment in Language Education and  I am sharing it with my annotations. https://acrobat.adobe.com/link/review?uri=urn:aaid:scds:US:efcf3a6a-dfbe-4623-bd66-141073b44509

Beeling exploits the possibility of having the reading passage as a model not only of accurate written language but also for spoken language. Besides, it is very good for differentiated instruction since students can have access to the written text and follow it in the audio. The fact that besides audiobooks , it also uses songs makes it even better for those students who besides being auditory are also into music. And that´s how I would use it, for differentiation. I would use this in both modalities: in- person and online since it will work fine in both. Individuals have different paces and different reasons for Reading, some times I would make use of the exercises after the Reading texts and others I would allow learners to read and show their understanding by creating a poster or a song or something like that. 

Duolingo, allows you to meet different purposes of why you are learning the language ( as survival English or to get a Certificate of your language proficiency), for my adult learners it is perfect. The way it combines gamification, mini lessons and a time- progress management system makes it really good for learners of all kinds. I think this is more appropriate to work online and at your own pace. 

Read Aloud combines several features that i think are important when you want to develop spoken skills. First, listen to a model, then shadowing reading which allows students not only to recognize and produce specific sounds but mostly to produce the appropriate intonation and rhythm.  That´s how I have been using it in my B2first course preparation. The additional  possibility for learners to record their own voices is good but what is best is to receive specific feedback on students´production so they know what needs to be improved. 

I think I´ll use it in an online class mostly but not exclusively since students need to understand certain features of spoken English to make the most out of this app and then by working on their own they can have as much practice as they want.