1. I created a plugin for Amazon ads. Currently (Jan 2020) I am getting about 35% fill rate and a CPM just under $1.00 for banner ads. The interstitial ads CPM is just above $1.00 so I don't think it would be worth it for that, but it does support it. Amazon is still CPI (Cost per impression).
I am only using it on the Amazon app store so I have no idea how it will behave on the Google Store.
It can be found here for those that are interested:
2. I also have a Ironsource plugin available. It is a couple iteration newer than the version I ran for the Appodeal vs Ironsource blog post. Although my opinion still stands that Appodeal is a better mediation partner (similar revenue but better reporting, support, and console), I have put it up on github for those that are interested.
Both plugins are for Android only for now and both are using the latest version of their respective api.