diff --git a/AppDebug.md b/AppDebug.md
index c28d95f..45a63a3 100644
--- a/AppDebug.md
+++ b/AppDebug.md
@@ -1,5 +1,6 @@
-# Application debugging
-In debugging a BOINC application,
+# Application testing and debugging
+
+In developing a BOINC application,
 you need to make sure that it interfaces properly with the BOINC client.
 You can do this in stages, as follows:
 
@@ -29,7 +30,7 @@ To do this:
 * Run your app.
 * To suspend your app, write "\<suspend/>" to msgs.txt.
  You need to do this atomically, e.g. write "\<suspend/>" to another file,
- then copy that file to msgs.txt.
+ then rename that file to msgs.txt.
  "cat > msgs.txt" doesn't work.
 * Similar for \<resume/> and \<abort/>.
  Verify that they all work.
@@ -38,7 +39,21 @@ To do this:
 
 Once your application works in standalone mode,
 you can test it under the BOINC client, but without a project server.
-This will exercise the various forms of interaction with the client.
+This will exercise the interaction with the client.
+
+### Simple way (no XML files)
+
+* Put a copy of the BOINC client and your application in a directory.
+* Create a subdirectory ```slots/app_test```.  Put your app's input files there (logical names).
+* Run ```boinc --app_test foo``` where ```foo``` is the application filename.
+* The client will run your application.
+  When it's done, the output files (and stderr.txt) will be in ```slots/app_test```.
+
+Note: if you want, the directory can be a BOINC data directory.
+In that case your application will coexist with existing jobs
+(it might not run right away).
+
+### Less simple way
 
 This example assumes that your executable name is **test.exe**,
 and that it has an input file with logical name **in** and physical name **input.txt**,
@@ -82,6 +97,8 @@ When the job is done,
 check **projects/test.test/output.txt** to verify that it worked.
 Your app's stderr output will be somewhere in client_state.xml.
 
+### Running under a debugger
+
 If your app isn't working, there are two ways to debug it.
 First, if you put
 ```xml