Kostya,
You may remember our brief conversation in a different thread/forum about what is considered to be what type of storage on Android phones.
I am more and more convinced that what my phone refers to as "SD card" under Settings -> Storage -> [particular app], - is the microSD card. On this phone (Droid Razr M, now 2+ y.o. model), a bunch of things are modified from the "stock" Android. In particular, the option of App2SD for apps is forbidden ( on 4.1.* and 4.2.*). So, one cannot install apps on the extrernal microSD card (on the unrooted phone), even those that are designed with that capability.
Speaking of the storage, - I thought you might be amused to read that there is a class-action law suit filed against Apple for deceiving advertisement with respect to the storage space available on the iPhones:
http://www.forbes.com/sites/gregorymcneal/2014/12/31/apple-faces-class-action-lawsuit-over-ios8-storage/I think, Android devices (at least phones, and I can speak of those for Verizon in the US), - are also guilty of some of those sins.
