Is a gem ready for Rails 4 or 5?

Rails 4: 615 ready, 38 not ready, and 433 unknown
Rails 5: 163 ready, 11 not ready, and 912 unknown

Gems ready for Rails 5

Name Status Rails 4 Notes Rails 4 Status Rails 5 Notes Rails 5 Status or notes updated
font_assets ready

running on our 4.2 app for some time

ready

Not dependent on rails

6 months ago
font-awesome-rails ready

https://github.com/bokmann/font-awesome-rails/issues/45

ready

since version 4.5.0.1

almost 3 years ago
foreman ready

-

ready

when not bundled in Gemfile. See https://github.com/ddollar/foreman/issues/688#issuecomment-326615890

6 months ago
geocoder ready

says so in readme

ready

see https://git.io/vXCdc

over 2 years ago
gon ready

_

ready

since version 6.0.1

almost 3 years ago
gretel ready

https://github.com/lassebunk/gretel/blob/master/gretel.gemspec

ready

See https://github.com/lassebunk/gretel/pull/66#issuecomment-216639544

about 2 years ago
haml_coffee_assets ready

see https://github.com/emilioforrer/haml_coffee_assets/blob/master/.travis.yml

ready

see https://github.com/emilioforrer/haml_coffee_assets/blob/master/.travis.yml

over 1 year ago
high_voltage ready

-

ready

since version 3.0

about 3 years ago
hipchat-api ready

Does not depend on Rails.

ready

Does not depend on Rails.

about 2 years ago
house_style ready

Was created for Rails 4 apps

ready

With no dependencies on Rails internals, house_style can be used safely with Rails 5

about 2 years ago
i18n-js ready

since gem version 3.0.0.rc8

ready

since gem version 3.0

almost 2 years ago
jbuilder ready

-

ready

5.2 from v2.8.0, 5.1 from v2.6.3, 5.0 from v2.5.0

6 months ago
jquery-rails ready

-

ready

https://github.com/rails/jquery-rails#installation mentions Rails 5.1. See also Taryn's comment

6 months ago
jquery-ui-rails ready

from gem version 4.0.2 (source)

ready

readme mentions Rails 5.0 (https://github.com/jquery-ui-rails/jquery-ui-rails#warning)

6 months ago
jwt ready

Running on our 4.2 app for some time.

ready

Not dependent on rails

6 months ago
kaminari ready

_

ready

since version 0.17.0

almost 3 years ago
keepr ready

see readme

ready

see readme

almost 3 years ago
launchy ready

does not depend on rails

ready

does not depend on rails

6 months ago
librato-rails ready

Running on our 4.2 app for some time

ready

5.0 support from v2.1.0

6 months ago
listen ready

Running on our 4.2 app for some time

ready

Not dependent on rails

6 months ago