How to stop service in one web app?

I created about 10 asp.net app in a web server. Every time I need to stop
service for all app in order to update one app. It has to be done in off hour.
Is there any way of stoping only one app?

For example, I developed a new version of myApp in local pc and ready to move to
web server.

I need to do the following steps:

1) in off hour, stop www publishing in web server (all web app will not run)

2) in web server, rename (or delete myApp)

3) copy entire myApp from local pc to web server

4) start www publishing

What you can do is to have 10 application pool and host each of the app in
dedicated app pool. when you need to update, just stop one of the app pool.

Thank you. This is first time of knowing about application pool.

Can you tell me more detail?

Try this online training -
http://www.microsoft.com/windowsserver2003/techinfo/training/iis.mspx

And 
Configuring Application Pools in IIS 6.0
http://www.microsoft.com/technet/prodtechnol/windowsserver2003/library/IIS/2a231
dcb-d786-4b6d-b3ba-bda04061a5e7.mspx