That's great but the peek option on the app really has to show the correct words. If you reveal on goodbye it just says kwa, but does not accept the answer it provides, since it needs kwa heri.
Please could you try for some more consistancy as this happens for a huge number of the peek suggestions.
I actually think you learn much more effectively if you don't peek ... just get it wrong, see the correct answer, and see if you get it right when it gets shown to you at the end. Getting "incorrect" costs you nothing except a few seconds. It's better than simply copying what's there and not seeing the word again for a long time because the system thinks you got it right.
That said, though, I agree ... since the hints are provided, they should at least be correct, and I do use them to understand words once I've already got them wrong.