There are some of the apps that I am using on my Android dual screen phone like:
Facebook messenger
Whatsapp
Instagram
Youtube
MX player
IMO
Apps lock
Apps backup
Hike
UC browser
Yes, I also faced the similar issue on my Android phone. Previously, it had KitKat after I updated it for lollipop I am noticing battery drain and there is also no space for more apps. It is better not to software update.