Ran app2egnine

eregon/app2engine

Gemspec
  Create team_dashboard.gemspec
Routes
  Edit config/routes.rb
Hierarchy
  Create lib/team_dashboard.rb
  Create lib/team_dashboard/
  Create lib/team_dashboard/engine.rb
  Create app/controllers/team_dashboard/
  Create app/models/team_dashboard/
  Create app/views/team_dashboard/
Initializers
  Comment config/initializers/secret_token.rb
  Comment config/initializers/session_store.rb
Generators
  Create lib/generators/team_dashboard/migrations/templates/
  Create
lib/generators/team_dashboard/migrations/migrations_generator.rb

Now your app should be ready to be used as an Engine
You have to add this to you main app's Gemfile:
gem 'team_dashboard', :path => 'path/to/team_dashboard'
You may want to remove the dependency to app2engine in the Engine's
Gemfile