How to transfer apps to your itouch?

Are there any ways to move apps to your ipod touch/iphone besides syncing the apps directly through the itunes library? Because alot of my apps on my itouch are not on my itunes library yet, and i don't want to lose those apps. If there's also a way to move those apps to the itunes library can someone please tell me? I'd really appreciate it.

1) Go preferences>Advanced on iTunes. Make sure "keep iTunes folder organized is checked."
2) Note the folder location of the iTunes media folder, and go find it.
3) Find the Mobile Applications folder inside that
4) Copy this folder to a flash drive or some other storage medium. The folder might be quite large, depending on how many apps you have. Mine is 8.4 GB with about 350 applications.
5) Make sure iTunes is installed on the new computer.
6) Plug flash drive into new computer.
7) In iTunes, go File>Add to Library. Navigate to your flash drive and select all the contents of that folder.

Now all your Apps are on the new computer. Unfortunately, the App data (such as saved games) will not make it.

Well dear, as far as I know, iTunes only can sync data from computer iTunes to apple models like iPad, iPod, iPhone, it is so hard to transfer data from device to iTunes library via iTunes. Have you ever done that successfully just using iTunes?

For me, I generally use a app called iTransfer to transfer data between iTunes and iOS devices without any limitation. Perhaps you can use iTransfer as a keyword to search in google to find a good app and what i use is leawo iTransfer.