What is the work of primary and secondary option in apk  

Consider the Benlotus app as having 4 browser tabs.

 

For Tab 1 (PRIMARY) you have choices for its homepage. This is for easy loading and convenience for the user, but you can still browse freely. 

Same with Tab 2 (SECONDARY) 

 

But for Tab 3 and Tab 4, automatic their homepage is in Chatbox and Musicbox. Since users need them running in the background, chatbox for new messages and live chat, and musicbox for music streaming in the background.

 

All 4 Tabs can load simultaneously. Allowing the users to just swipe to move around the forum, from browsing(depending on your choice for Tab 1 and 2 Homepages) then to chatting, and to music streaming.

benlotus app gamit ko ngayon ang masasabi ko lang mas maganda sya keysa sa browser