diff --git a/.travis.yml b/.travis.yml
index 7c572ee..b573b29 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,6 +13,7 @@ install:
 
 script:
   - script/build
+  - bundle exec danger
 
 before_deploy:
   - script/package
diff --git a/Dangerfile b/Dangerfile
new file mode 100644
index 0000000..96c0ee0
--- /dev/null
+++ b/Dangerfile
@@ -0,0 +1,38 @@
+# Sometimes it's a README fix, or something like that - which isn't relevant for
+# including in a project's CHANGELOG for example
+has_app_changes = !git.modified_files.grep(/mas-cli/).empty?
+# has_test_changes = !git.modified_files.grep(/Tests/).empty?
+
+is_version_bump = git.modified_files.sort == ["CHANGELOG.md", "mas-cli/mas-cli-Info.plist"].sort
+message(":bookmark: Version bump!") if is_version_bump
+
+# if has_app_changes && !has_test_changes && !is_version_bump
+#     warn("Tests were not updated", sticky: false)
+# end
+
+# Thanks other people!
+message(":tada:") if is_version_bump && github.pr_author != "phatblat"
+
+# Mainly to encourage writing up some reasoning about the PR, rather than just leaving a title
+if github.pr_body.length < 5
+    fail ":memo: Please provide a summary in the Pull Request description"
+end
+
+# Let people say that this isn't worth a CHANGELOG entry in the PR if they choose
+declared_trivial = (github.pr_title + github.pr_body).include?("#trivial") || !has_app_changes
+message("This PR might seem trivial, but every contribution counts. :kissing_heart:") if declared_trivial
+
+# Keep the CHANGELOG up-to-date
+if !git.modified_files.include?("CHANGELOG.md") && !declared_trivial
+    fail(":book: Please include a CHANGELOG entry. \nYou can find it at [CHANGELOG.md](https://github.com/mas-cli/mas/blob/master/CHANGELOG.md).", sticky: false)
+end
+
+# Make it more obvious that a PR is a work in progress and shouldn't be merged yet
+warn(":construction: PR is classed as Work in Progress") if github.pr_title.include? "[WIP]"
+
+# Warn when there is a big PR
+warn(":dizzy_face: Big PR") if git.lines_of_code > 500
+
+# Don't let testing shortcuts get into master by accident
+#fail("fdescribe left in tests") if `grep -r fdescribe Tests/ `.length > 1
+#fail("fit left in tests") if `grep -r fit Tests/ `.length > 1
diff --git a/Gemfile b/Gemfile
index c40482b..e99d81d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,4 +2,5 @@
 source "https://rubygems.org"
 
 gem "cocoaseeds"
+gem "danger"
 gem "xcpretty"
diff --git a/Gemfile.lock b/Gemfile.lock
index 688ae01..1391b4e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,13 +2,52 @@ GEM
   remote: https://rubygems.org/
   specs:
     CFPropertyList (2.3.6)
+    addressable (2.5.2)
+      public_suffix (>= 2.0.2, < 4.0)
     claide (1.0.2)
+    claide-plugins (0.9.2)
+      cork
+      nap
+      open4 (~> 1.3)
     cocoaseeds (0.8.3)
       colored2 (~> 3.1)
       xcodeproj (>= 0.28)
     colored2 (3.1.2)
+    cork (0.3.0)
+      colored2 (~> 3.1)
+    danger (5.5.8)
+      claide (~> 1.0)
+      claide-plugins (>= 0.9.2)
+      colored2 (~> 3.1)
+      cork (~> 0.1)
+      faraday (~> 0.9)
+      faraday-http-cache (~> 1.0)
+      git (~> 1)
+      kramdown (~> 1.5)
+      no_proxy_fix
+      octokit (~> 4.7)
+      terminal-table (~> 1)
+    faraday (0.14.0)
+      multipart-post (>= 1.2, < 3)
+    faraday-http-cache (1.3.1)
+      faraday (~> 0.8)
+    git (1.3.0)
+    kramdown (1.16.2)
+    multipart-post (2.0.0)
     nanaimo (0.2.3)
+    nap (1.1.0)
+    no_proxy_fix (0.1.2)
+    octokit (4.8.0)
+      sawyer (~> 0.8.0, >= 0.5.3)
+    open4 (1.3.4)
+    public_suffix (3.0.1)
     rouge (2.0.7)
+    sawyer (0.8.1)
+      addressable (>= 2.3.5, < 2.6)
+      faraday (~> 0.8, < 1.0)
+    terminal-table (1.8.0)
+      unicode-display_width (~> 1.1, >= 1.1.1)
+    unicode-display_width (1.3.0)
     xcodeproj (1.5.4)
       CFPropertyList (~> 2.3.3)
       claide (>= 1.0.2, < 2.0)
@@ -22,6 +61,7 @@ PLATFORMS
 
 DEPENDENCIES
   cocoaseeds
+  danger
   xcpretty
 
 BUNDLED WITH