Remove unwanted app which doesn't show delete icon

1. SSH to iPhone with root account, root's password is alpine
e.g. ssh -l root

2. cd to /Applications@ (/Applications@ is a symbolic link to /var/stash/Applications)
delete the the unwanted application directory (says, HelloWorld.app)
e.g. rm -r -f HelloWorld.app

3. The icon on the home screen exists until iPhone restart.

4. Power off and restart iPhone, the unwanted application is gone.