Are there any free desktop apps for voice to text converter?

There are a number of free Google Chrome plug-ins that do voice to text quite well. For a very basic text to sound you can also use Google. Just drop your text in Google translate and press the "Listen" button. Use for example Audacity to record the system audio and export it to a sound format.
All these examples are free.

Hi Sandip,

It's not desktop, but you can use https://dictation.io/ (web based, no download). There are lots of solutions for text to voice, but for both I'd say it depends on your use case. If you're looking to use these tools for a project (as opposed to personal use) your best bet is to use an API (dozens available, depends on your specific needs.

Good luck.

Best,

Hugh

Simon: Open-Source Speech Recognition http://simon-listens.blogspot.com/

Dragon Speech Recognition software is probably the best known.

Not free, but close to it is this application: http://www.nch.com.au/verbose/

If you have never tried using automatic dictation software, then here's an easy way to do so. Use your web browser to visit www.talktyper.com and you're ready to start speaking.

You'll need a supported browser (Chrome is recommended), and you'll also need a microphone on your PC of course. Then just start speaking, one sentence at a time. Your spoken text appears in the top half of the window, ready for you to edit if required, and then to copy down to the main document in the lower half of the window. Once you've assembled an entire document or letter, you can print, email, or copy it to the clipboard for subsequent use.

Talktyper isn't the best dictation software I've ever used. And because it sends your speech to a remote server in order to deciper, it's probably not the most secure either. But it's quick, simple, free, and a great way to try out the technology if you've never used such a thing before. And it'll keep the kids entertained for hours too.

It depends on the language also. In my experience I didn't meet free this type of app but I operated enterprise sized Call Centers used Alcatel voice to text converters.

google on any android phone or the microphone selection in google search

https://dictation.io/