@danielnewy - IMHO, these are good for creating an Android-based Magic Mirror project. There are a lot of development boards out there that run various flavors of Android and they likely can be used with these apps with little difficulty. If all you want out of your mirror is the basics (newsfeed, weather, stocks, exchange rates, date & time, calendar) then these apps will likely work and be very easy to install.
If you’re an existing Android developer, then these may be the way to go. If you’re just getting started, I would stick with the Raspberry Pi and configuration files that are the prevalent method around here (unsurprisingly, since the forum was started to provide a community for the Raspi Mirror builders).
Looking at the Mirror Feeds site, for example… there are already modules that perform all of those features, plus a lot more. That’s the beauty of the module framework: multiple developers are adding features all the time.
To be honest, I would recommend building a Raspberry Pi based mirror and proceeding that direction. Unless you can think of a reason why you need to go with Android.