I was googling for an available update solution and tried something and it worked.
Here's how I did
went on: http://appgravity.com/android-apps/p...are-docmaster#
clicked on the FREE button
got a QR code which appeared > Scanned it with barcode reader on my phone.
Got another link with the Barcode Scanner (just donwnload a barcode scanner from google play if you don't have one) and it redirected me to Google Play for update.
I'm using HTC One E8 (china unicom version), don't know if it'll work on others, but it's worth a try.
Don't for get to click the thanks button if this helps you