Roku Scene Graph

I have some doubts regarding roku applications on brightscript and scengraph both for roku tv, a basic knowledge from your side will help us,we just have doubts on 2 topics, we have developed our application but it just requires few things to get completed, actually we have 2 application

1. one with the login flow and

2. the other with the grid screen .

So we just need a guidance on how we can combine both the application so that after the login, a user is redirected towards grid screen, the coding is completely in rokus scenegraph.