Right now, when you try to add it to a Rails 4 project and do rails g tandem you get the following error:
/Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activemodel-4.0.0/lib/active_model/deprecated_mass_assignment_security.rb:14:in `attr_accessible': `attr_accessible` is extracted out of Rails into a gem. Please use new recommended protection model for params(strong_parameters) or add `protected_attributes` to your Gemfile to use old one. (RuntimeError)
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/tandem-0.2.5/app/models/tandem/content.rb:10:in `<class:Content>'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/tandem-0.2.5/app/models/tandem/content.rb:2:in `<module:Tandem>'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/tandem-0.2.5/app/models/tandem/content.rb:1:in `<top (required)>'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:423:in `load'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:423:in `block in load_file'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:615:in `new_constants_in'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:422:in `load_file'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:323:in `require_or_load'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:462:in `load_missing_constant'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:183:in `const_missing'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/tandem-0.2.5/app/helpers/tandem/pages_helper.rb:7:in `included'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/actionpack-4.0.0/lib/abstract_controller/helpers.rb:165:in `include'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/actionpack-4.0.0/lib/abstract_controller/helpers.rb:165:in `block in add_template_helper'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/actionpack-4.0.0/lib/abstract_controller/helpers.rb:165:in `module_eval'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/actionpack-4.0.0/lib/abstract_controller/helpers.rb:165:in `add_template_helper'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/actionpack-4.0.0/lib/abstract_controller/helpers.rb:95:in `block in helper'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/actionpack-4.0.0/lib/abstract_controller/helpers.rb:94:in `each'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/actionpack-4.0.0/lib/abstract_controller/helpers.rb:94:in `helper'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/tandem-0.2.5/lib/tandem/engine.rb:15:in `block (2 levels) in <class:Engine>'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:38:in `instance_eval'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:38:in `execute_hook'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:28:in `block in on_load'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:27:in `each'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:27:in `on_load'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/tandem-0.2.5/lib/tandem/engine.rb:14:in `block in <class:Engine>'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `instance_exec'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `run'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:55:in `block in run_initializers'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:150:in `block in tsort_each'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:219:in `each_strongly_connected_component_from'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:182:in `block in each_strongly_connected_component'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:180:in `each'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:180:in `each_strongly_connected_component'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:148:in `tsort_each'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:54:in `run_initializers'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/application.rb:215:in `initialize!'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /Users/treybean/Sites/one_eighty_tacos/config/environment.rb:5:in `<top (required)>'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `block in require'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:213:in `load_dependency'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/application.rb:189:in `require_environment!'
from /Users/treybean/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands.rb:45:in `<top (required)>'
from bin/rails:4:in `require'
from bin/rails:4:in `<main>'
Right now, when you try to add it to a Rails 4 project and do
rails g tandemyou get the following error: