When I enter some text and press and hold on it then context menu is presented with items like cut,copy,select text and so on.
Is there any way to add my own custom item to this context menu ? I do not how this things works but I guess that should be possible to register something in the manifest just like registering activities and broadcasts . . .
Thanks,
Any ideas are wellcomed

Only for widgets in your own activities, not for the system as a whole.
Also,
EditTextis problematic even for your own activities, as some device manufacturers are bypassing the normal context menu system, so you can’t add to them.That being said, for your own activities, just follow the instructions to create a context menu for the widgets of interest.