Why some Apps are not movable to SD card

Question

Dear gents

I am struggling with annoying issue on Android Oreo at Samsung S7 related low internal memory.

If you navigate app in settings and go to aj app then memory there is sometimes option to move to external SD card an app.

But not all app are movable!! which is annoying especially those big ones.

I can imagine there are system app which can not be movable but for instance bulk chrome browser is not movable such option in app settings does not exist at all.

My question to forum would be.

In what depends if app is movable or not? How I can force or overide some app capabilities to be able move to SD card?

I can imagine there is some systém app must be inbuilt or maybe app developer does not want app to be installed on SD card.

But my question is again why we have such annoying feature in Androids OS several years and how to overide or influence such crap.

I guess rooting of Android could help but my phone is under warranty so I do not want to do it by such way.

Any advice would be highly welcomed. 
Many thanks

Regards

James Watson · Accepted Answer

I found some descriptions about that manifest attribute in the official developer guide. 

Beginning with API Level 8, you can allow your application to be installed on the external storage (for example, the device's SD card). This is an optional feature you can declare for your application with the **android:installLocation** manifest attribute.

marco sarli · Answer

Some apps can simply not be moved. Try setting the sd card as default storage and you should be able to gain some space and you will be able to store more stuff on it

andy220 · Answer

No this is not my problem. Regardless default installation place is external memory some apps are going to internal one and they are not movable.I found that every app has attribute in apk install file where are developers preventing to save app to external storage. Weird crazy but as is.

James Watson · Answer

As far as I know, developers may set an attribute to allow apps to be installed on the external storage or to be moved to the external storage. 
But if he/she has not set that preference, the app will be installed on internal storage and it won't be movable.

andy220 · Answer

But gents is it possible somehow tweak such app installation package without rooting?I want just freedom and move bulk apps such as chrome to external memory to release scarce internal memory at Samsung S7.

Thanks