BASED on: https://gist.github.com/gboudreau/94bb0c11a6209c82418d01a59d958c93

pretty much the same text. I just added some few screenshots and changed the javascript code to show only the secret text.

1. Install Authy APP from Chrome Web Store Thi is the App, not the extension.
2. Open Authy and log in, so you can see the codes being generated for you
3. Go to Extensions page in your browser (chrome://extensions/ or Menu -> More tools -> Extensions)
4. Tick developer mode in top right corner

5. Find Authy from the list, remember this is the App and not the extension, and then click on main.html

6. Chrome developer tools with Console selected should open. If it didn't, go to Console tab.

7. Paste following code and press enter:

/* base32 */
/*
Copyright (c) 2011, Chris Umbel

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
var charTable = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
function quintetCount(buff) {
  var quintets = Math.floor(buff.length / 5);
  return buff.length % 5 === 0 ? quintets : quintets + 1;
}
encode = function(plain) {
  var i = 0;
  var j = 0;
  var shiftIndex = 0;
  var digit = 0;
  var encoded = new Array(quintetCount(plain) * 8);
  /* byte by byte isn't as pretty as quintet by quintet but tests a bit faster. will have to revisit. */
  while(i < plain.length) {
      var current = plain[i];
      if(shiftIndex > 3) {
          digit = current & (0xff >> shiftIndex);
          shiftIndex = (shiftIndex + 5) % 8;
          digit = (digit << shiftIndex) | ((i + 1 < plain.length) ?
              plain[i + 1] : 0) >> (8 - shiftIndex);
          i++;
      } else {
          digit = (current >> (8 - (shiftIndex + 5))) & 0x1f;
          shiftIndex = (shiftIndex + 5) % 8;
          if(shiftIndex === 0) i++;
      }

      encoded[j] = charTable.charCodeAt(digit);
      j++;
  }
  for(i = j; i < encoded.length; i++) {
      encoded[i] = 0x3d; //'='.charCodeAt(0)
  }
  return encoded.join('');
};
/* base32 end */
function hexToInt(str) {
  var result = [];
  for (var i = 0; i < str.length; i += 2) {
      result.push(parseInt(str.substr(i, 2), 16));
  }
  return result;
}
function hexToB32(str) {
  return encode(hexToInt(str));
}

getTotps = function() {
var totps = [];

console.warn("Here's your Authy tokens:");
appManager.getModel().forEach(function(i) {
  var secret = (i.markedForDeletion === false || !i.secretSeed)  ? i.decryptedSeed : hexToB32(i.secretSeed);
  var totp_uri = 'otpauth://totp/' + encodeURIComponent(i.name) + '?secret=' + secret + '&issuer=' + i.accountType + '&digits=' + i.digits + '&period=10';
  console.group(i.name);
  console.log('secret:');
  console.log(secret);
  //console.log('TOTP URI: ' + totp_uri);
  var qr_code = 'https://www.google.com/chart?chs=200x200&chld=M|0&cht=qr&chl=' + encodeURIComponent(totp_uri);
  //console.log('QR code: ' + qr_code);
  totps.push({
      name: i.name,
      totpURI: totp_uri,
      qrCode: qr_code
  })
  console.groupEnd();
});
//console.log(JSON.stringify(totps));

return totps;
}
getTotps()

8. What you should see is something like this:

9. All your Authy tokens will be displayed in the Console; either copy-paste the secret to other password managers.