I re-wrote my old app in fat-free framework. Everybody who used this app have bookmark http://www.domain/app/index.php This url now does not work in F3. Can I redirect index.php to http://www.domain/app/ ? Thanks.
You can define the redirection at the framework level:
index.php
file:$f3->redirect('GET /index.php','/');
[redirects]
GET /index.php = /