Stable version 2.4.0 which is Joomla 4 ready.

jedchecker.xml

@@ -1,12 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
-<extension type="component" version="3.9" method="upgrade">
+<extension type="component" version="4.0" method="upgrade">
   <name>COM_JEDCHECKER</name>
   <author>Joomla! Extensions Directory</author>
   <creationDate>2020-08-22</creationDate>
-  <copyright>Copyright (C) 2017 - 2020 Open Source Matters, Inc. All rights reserved.</copyright>
+  <copyright>Copyright (C) 2017 - 2021 Open Source Matters, Inc. All rights reserved.</copyright>
   <authorEmail>[email protected]</authorEmail>
   <authorUrl>https://github.com/joomla-extensions/jedchecker</authorUrl>
-  <version>2.3.0</version>
+  <version>2.4.0</version>
   <license>http://www.gnu.org/copyleft/gpl.html GNU/GPL</license>
   <description><![CDATA[JED Checker will check your extension files and will let you know in advance if there are any possible problems with your extension for submitting to the JED]]>
   </description>

manifest.xml

@@ -5,12 +5,31 @@
         <description><![CDATA[JED Checker will check your extension files and will let you know in advance if there are any possible problems with your extension for submitting to the JED]]></description>
         <element>com_jedchecker</element>
         <type>component</type>
-        <version>2.3.0</version>
-        <client>site</client>
-        <infourl title="JED Checker Extension">https://github.com/joomla-extensions/jedchecker/releases/tag/2.3.0</infourl>
+        <version>2.4.0</version>
+        <client>administrator</client>
+        <infourl title="JED Checker Extension">https://github.com/joomla-extensions/jedchecker/releases/tag/2.4.0</infourl>
         <downloads>
-            <downloadurl type="full" format="zip">https://github.com/joomla-extensions/jedchecker/archive/2.3.0.zip</downloadurl>
+            <downloadurl type="full" format="zip">https://github.com/joomla-extensions/jedchecker/archive/refs/tags/2.4.0.zip</downloadurl>
         </downloads>
-        <targetplatform name="joomla" version="3.[6789]" />
+        <tags>
+            <tag>stable</tag>
+        </tags>
+        <targetplatform name="joomla" version="3.([789]|10)" />
+    </update>
+    <update>
+        <name>JED Checker Extension</name>
+        <description><![CDATA[JED Checker will check your extension files and will let you know in advance if there are any possible problems with your extension for submitting to the JED]]></description>
+        <element>com_jedchecker</element>
+        <type>component</type>
+        <version>2.4.0</version>
+        <client>administrator</client>
+        <infourl title="JED Checker Extension">https://github.com/joomla-extensions/jedchecker/releases/tag/2.4.0</infourl>
+        <downloads>
+            <downloadurl type="full" format="zip">https://github.com/joomla-extensions/jedchecker/archive/refs/tags/2.4.0.zip</downloadurl>
+        </downloads>
+        <tags>
+            <tag>stable</tag>
+        </tags>
+        <targetplatform name="joomla" version="4.[0123]" />
     </update>
 </updates>