You don't need iTunes if you don't want too once you have iFunbox installed on your existing OS, or simply using it as an option if there is a problem on your iTunes. So you have a second option which is iFunBox to download and install application for your iOS based devices.
And no need to jailbreak your device to use iFunbox to further install the apps you have purchased. And you don't need to install installous to install unsigned or unofficial .ipa based on AppSync. And you can easily install apps in batch easily using iFunBox app that is available for Windows and Mac.
How to install Cracked iPA Apps Without iTunes Using iFunBox1. Once you've download iFunbox, open it and then connect your device to your computer using USB. You will see your device content in the left pane of the window.
2. And then click on User Applications from your device, and then all your installed apps will appear. Now right-click anywhere on the application area and then choose Install App [AppFastIn].
3. Then a new popup window will be asking you to choose iPA package. so go to .ipa app you wish to install and then hit open.
4. iFunbox will begin the installation, once it finishes, iFunbox will notify you.