When ‘I feel myself’ is introduced the female voice says something intelligible instead of ‘mich’.
And I’m not sure about the inclusion of ‘myself’ in these sentences as I don’t think its consistent with the ‘you’ sentences. There’s ‘me myself’ but not ‘you yourself’ for the equivalent phrase.
There’s quite a few repetitions of ‘Ich muss nicht’ one after another and then it goes straight to
and I don’t think ‘verbessen’ was introduced.
‘Mir sorgen machen’ is introduced as ‘to worry’ - should this be ‘to worry me’? And on ‘nicht mir sorgen machen’ the female voice really drags out ‘mir’.
Not sure about ‘when I not’ as a prompt. Its used for ‘wenn ich nicht’. 
“To worry about making mistakes” is translated “Mir sorgen machen, Fehler zu machen”.
I tend to say “Sorgen machen zu Fehler machen” instead.
Probably because I tend to think of “to worry” as generic instead of referred to me, and “zu” as the translation of “about” and put it in the same position.
So, just curious: would that be wrong or it would also be an acceptable alternative option?
Also I’m not sure I’ve heard “keine” introduced before.
But it suddenly appeared in the “I don’t need to worry” - “Ich muss mir keine Sorgen machen” (instead of “nicht” , which I had thought of)
That doesn’t sound right to me - I can’t comment on the beginning, but I’m fairly sure it should be Fehler zu machen - hopefully someone with more German knowledge than me will comment 
kein/keine used to trip me up a lot when I first started learning German, and it still does occasionally if I’m thinking in English instead of German, but basically if it means “nothing of a thing” - then it’s not nicht but kein/keine
e.g. I have a dog - ich habe einen Hund
I don’t have a dog - ich habe keinen Hund not ich habe nicht einen Hund
‘Make mistakes’ is introduced by the English voice (the German for ‘make mistakes’ is…) after it has already appeared (unannounced! 
) in the practice.
I think some of the prompts might be a bit mixed up for ‘es ist mir egal wenn ich Fehler mache’. I think sometimes its ‘I don’t care if I make mistakes’ (which works) but sometimes I think its ‘I don’t care about making mistakes’ which I think was ‘est ist mir egal Fehler zu mache’.
The prompts include ‘its a good thing’ for responses of ‘es ist gut’. Just wondering if the prompt would be better as ‘its good’ and without mentioning a ‘thing’
The male utterance of ‘mehr’ on its own is a bit odd.
‘I’m trying to practice speaking more’ is given as ‘ich versuche mehr zu sprechen’ which is ‘I’m trying to speak more’ (and doesn’t include ‘practice’).
The male pronunciation of ‘damit nicht’ is gobbledegook. 
The English pronunciation of ‘I can’ on its own is a bit like ‘I carn’, then the German male sounds like there is a ‘t’ on the end of ‘ich kann’ and there’s a bit of a buzz and click somewhere around here.
The male pronunciation of ‘könntest du’ is a bit messed up when he says it on its own.
The male pronunciation of ‘can’ on its own is gobbledegook.
These don’t seem to match:
And sometimes it’s ‘ich bin nicht sicher ob ich dir helfen kann’ and sometimes it’s ‘ich bin mir nicht sicher ob ich dir helfen kann’
Sometimes ‘zu nehmen’ is missing from the German when the English prompt includes ‘to take time’.
You’re right, the phrases don’t match. The German says “Because I can’t remember how I wanted to say what I wanted to say”, so it still kind of makes sense, but in my opinion the German sentence should be
Weil ich mich nicht erinnern kann, wie man sagt was ich sagen wollte.
Ich bin mir nicht sicher is more correct, but here it’s completely fine to leave out the reflexive pronoun. (The same would be true for the question “Are you sure” → Bist du (dir) sicher?)
I think when the female voice says ‘ich finde’ on its own she might miss off the ‘e’ at the end.
And the male voice doesn’t pronounce ‘dass du’ on it own right, and he pronounces 'es’on its own as gobbledegook.
When it presents “mehr” it sounds like “mehrm” or “mehrn” to me (for both voices)!
While it doesn’t do that when it’s “nicht mehr” (right after).
The male pronunciation of ‘noch viel‘ on it’s own is more like ‚doch viel‘