Ah nice, either I missed that or it’s new in 4.8. We’re still using 4.7. 
If I’m not mistaken, it’s new in 4.8… cause I never saw it in 4.7 or at least never notices it.
It seems new in 4.8. I don’t see compressed package in 4.7.
I have both 4.7 and 4.8 installed.
you might be right because I have 4.8.1 and I don’t recall if it was there in 4.8.0… nonetheless, it’s great to have it in there 
The package compressing reduced the obb file size to about 1/3. From 37MB to 12.MB. The total size APK + OBB is 35MB now(ETC1). The ASTC has the same size as ETC1 after compressed. It is also total 35MB size.
But the Program APK is still very large.
The most part of it is libUE4.so. It is about 20MB even after apk compressed (61.2MB uncompressed). It occupates nearly 85% size of total APK.
I only linked “Core”, “CoreUObject”, “Engine”, “InputCore” , “Paper2D” modules. (I only added “Paper2D” module. Others are defaults.)
I don’t think I can reduced the modules further.
The Engine Moduel is the biggest. It almost contains 95% size.
as I stated above, I know that Epic will improve on many front as far as mobile is concern.
Change project from Pure Blueprints to C++ will reduce the libUE4.so’s size a little(Because it links less modules than Blueprints by default). About 15MB.
But after apk compressed it is only about 5MB difference.
The big size “.so” will drain a lot of RAM at runtime. And slow down the startup time.
There is also more time needed to run or deploy app from engine to device, because there is more file processed and uploaded to the device. There should be possibility to exactly specify which part of engine should be load to device and some of the thinks that are not used on mobile or in project should be cut off. The problem is bigger for bigger projects because it slowdown each of iteration of testing at mobile device.
Umm, UE Is The Next Level, The Next Stage, Who The Fk Would NOT Take That Opportunity To Be A Part Of That Greatness, That Being Said, My Mobile Game Just Hit 4gb XD, Simply Gotta Reduce It With Research, Easy