Thank you for fixing the broken image links. I have been also looking for this. One thing I'm unsure of, it the guide up to date? The original thread is bit old. Is there any smartphone guide available? Many doesn't have any desktop devices.
I have tried the latest version of gpg4win and the user interface seems almost the same. There are some changes, but I guess you won't face issues understanding the new UI. If you face difficulties understanding something, you can post here and many members will help you including me.
About the Android version: Currently I am testing an Android, if I can do all the necessary steps with the app I am trying, I will share in this community. But I guess most of us use Desktop.
I suggest you complement it with your own experience in practising it, as in the past,
mdayonliner wrote its version by using my thread
PGP/GPG Signed Message - Public Key in Indonesian as a reference*.
In my thread, is intended for several OS with several methods and applications:
I have tried it myself. I have written a beginner tutorial in the Bengali version. Since the English version is already available, I did not want to write it again. I fixed the broken images instead. Moreover, I do not have several OS at this moment. But, I will try if I can.