The most significant thing that happened was that the Lightning Network concept was published, which is very similar to the original Amiko Pay concept. I examined the Lightning Network and came to the conclusion that it achieves the same things as Amiko Pay, while it requires much smaller changes to Bitcoin to become completely "trust-free". So, my plan is now to implement the Lightning Network concept in Amiko Pay.

Since the Lightning Network still requires some Bitcoin features that currently don't exist yet, I went looking for ways to deal with this absence. Read this thread for a description of the design I made for this.