Homescreen

On the Home screen you see your notifications, present box, etc.

The brown bar on the top left gives you recommendations on what to do next (play a live, clear daily missions, etc.). The top right bar shows your rank, LP (used to play lives) and EXP. The plus button refills your LP using candy, lollipops or discs.

Below the rank bar is (from left to right) daily missions, chat, news, and present box. The chat is not an ingame chat.
Below that, the banner shows the latest scout as well as any special news. And lastly below that, the curtained box has the latest event.

The bottom menu buttons are the different areas of the game:
Home - returns you to the home screen
Story - read the main story, as well as affection and event stories
Live - play lives
I-Chu - View, change, and level up your cards
Scout - scout for new cards
Shop - buy discs, refill LP, and buy more album space using discs
Friends - view friend list, send and accept friend requests, view and send messages
Other - view and adjust settings for the game and lives, view/change your profile