I dont use any fancy android local storage things, i need a clear way to write, read into internal/external memory as user chooses on which he wants to install it. Problem is kiktak (android 4.4) doesnt allow third party apps to write to external sd cards (and maybe to internal too) so what opportunities do i have?

I'm pretty sure it does. WRITE_EXTERNAL_STORAGE is marked as API level 4. I have myself never used nor plan to use external storage but I'm interested in knowing more. What have you tried?

android 4.4 builtin file explorer doesnt open any file but deletes them if you want but no other functionality

This seems reasonable to me. What other functionality would you expect? Running the appropriate activity? Sure, it would be expected on desktop Open with NPP or something.

Android can even infer the mimetype I guess... but I don't think it fits with the usage model.

Nonetheless, the files are there. Or not?

i tried some other file explorers from playy store but you cant delete files or write anything

That's odd. I don't expect the file explorer to give you a way to save a .txt file or something. It's just not in the mindset.

Watch out, maybe you have forgot to add application path to the dir you have been provided. It's a bit stupid. Maybe it's the same for external.

I dont use any fancy android local storage things, i need a clear way to write, read into internal/external memory as user chooses on which he wants to install it. Problem is kiktak (android 4.4) doesnt allow third party apps to write to external sd cards (and maybe to internal too) so what opportunities do i have?

Are you talking about your app reading/writing files in external storage?

Or are you talking about your users wanting to move your app to external storage in order to save space?

I think people think you're talking about the first one, in which case WRITE_EXTERNAL_STORAGE should do it as they have said.

But I think maybe you're asking for the latter. If so, then it's a simple change to the manifest.

<manifest xmlns:android="blah" 
		  package="blah" 
		  android:versionCode="1" 
		  android:versionName="1.0.0"
		  android:installLocation="auto"
		  >

Adding the android:installLocation="auto" allows users to move your app install to their SD card.

third party apps are blocked by athat version of android so it doesn't allow them to delete/modify a file from external sd.