the latest version of the tool is stored in the project file

Build/Components/4DPop AppMaker.4dbase/Info.plist

@@ -6,15 +6,15 @@
     <key>NSHumanReadableCopyright</key>
     <string>©vdl 2009-2024</string>
     <key>CFBundleVersion</key>
-    <string>572</string>
+    <string>575</string>
     <key>CFBundleDisplayName</key>
     <string>4DPop AppMaker</string>
     <key>CFBundleShortVersionString</key>
     <string>20R5</string>
     <key>CFBundleGetInfoString</key>
     <string>20R5</string>
     <key>CFBundleLongVersionString</key>
-    <string>20R5 (571)</string>
+    <string>20R5 (574)</string>
     <key>CFBundleName</key>
     <string>4DPop AppMaker</string>
   </dict>

Info.plist

@@ -6,15 +6,15 @@
     <key>NSHumanReadableCopyright</key>
     <string>©vdl 2009-2024</string>
     <key>CFBundleVersion</key>
-    <string>572</string>
+    <string>575</string>
     <key>CFBundleDisplayName</key>
     <string>4DPop AppMaker</string>
     <key>CFBundleShortVersionString</key>
     <string>20R5</string>
     <key>CFBundleGetInfoString</key>
     <string>20R5</string>
     <key>CFBundleLongVersionString</key>
-    <string>20R5 (571)</string>
+    <string>20R5 (574)</string>
     <key>CFBundleName</key>
     <string>4DPop AppMaker</string>
   </dict>

Project/4DPop AppMaker.4DProject

@@ -1,3 +1,4 @@
 {
-	"$comment": "The project file let you override the location for most folders"
-}
+	"$comment": "The project file let you override the location for most folders",
+	"$4DPopAppMakerToolVersion": "20R5"
+}

Project/Sources/Classes/AppMaker.4dm

@@ -118,14 +118,25 @@ Function run($withUI : Boolean) : Boolean
 
 		This:C1470._callBarber("⚙️ "+Get localized string:C991("CompilationAndGeneration"); Barber shop:K42:35)
 
-		var $lastbuild : 4D:C1709.File
-		$lastbuild:=This:C1470.database.databaseFolder.file("lastbuild")
-		$lastbuild.create()
+		var $project : 4D:C1709.File
+		$project:=Folder:C1567("/PACKAGE/Project"; *).files().query("extension = .4DProject").first()
 
-		If ($lastbuild.getText()#This:C1470.motor.branch)
+		var $o : Object
+		$o:=JSON Parse:C1218($project.getText())
+
+		If ($o.$4DPopAppMakerToolVersion#This:C1470.motor.branch)
 
 			This:C1470.database.clearCompiledCode()
-			$lastbuild.setText(This:C1470.motor.branch)
+
+			$o.$4DPopAppMakerToolVersion:=This:C1470.motor.branch
+			$project.setText(JSON Stringify:C1217($o; *))
+
+		End if 
+
+		// Delete old file if any
+		If (File:C1566("/PACKAGE/lastbuild"; *).exists)
+
+			File:C1566("/PACKAGE/lastbuild"; *).delete()
 
 		End if