Create a new tales project using "fan tales new" command

fan tales new newapp

An app directory newapp/ is created for you

1. Open F4 IDE, choose a location for workspace other than the project location
2. Select File->new->Fantom Project
3. Type your project name("newapp" in this example) in the project name box.
4. Select "Create project from existing location (from existing source)"
5. Click on browse and choose your app directory
6. click finish
   
7. Open fan/build.fan, Right click anywhere on the editor and select "Run as->Fantom class". This should build the pod for the first time
8. Open fan/Debug.fan and select "Debug As->Fantom class"

That's it. now Just modify the classes as usual and and debug-away :)