> I have bought the Pro version of the application, but I can't download it. What can I do?

If you just purchased the application, you may have to wait a few hours to be able to download it, depending on how long it takes Google to validate the transaction.

If you purchased it a few days ago and still can't install it, what you can try to do is remove the cache of the PlayStore application.

> I have added the transcription for a word, but the app isn't using this information for the audio.

The transcription field allows you to add additional information on a word. This can't be used for audio, simply because there is no Text-to-speech system handling this kind of information (yet).