Drop Down Menu (News_category a', category b')

[Approgramatistoi]

I have many requests to create a drop down menu in my news apps.
eg. In news application:

Feed
_category feed a'
_category feed b' (etc)

Feed
_category feed a'
_category feed b' (etc)

if be this possible added would be very useful and would appreciate the users!
Many apps has this feature