Add welcome page
Add default_scope to Tweet

which sort of 'created_at'
Create user page
Modified appearance
Solve n + 1 problem
Create Following
Delete user's tweets when user is deleted
Modified appearance

With cosmetic changing
Add gems for debug
Enable to follow and unfollow user
Refactoring
Require to sign in at users#show
Don't display a button when current_user is same as target_user
Display only tweets of following users or current_user
Add an `active` scope to user
Display active users at home#index
Redirect to previous page after send tweet instead of root path
Modify appearance of a "tweets/form" patial to panel
Create a "users/list" partial
Add link to current user's page