RipDev claims that InstallerApp will allow you to download jailbreak apps from "Cydia" and "Installer" app onto your computer and install them on your jailbroken iPhone.
One of the biggest problems with jailbreaking is that whenever you update your jailbroken iPhone with the latest firmware update, you end up losing the jailbreak as well as the jailbreak apps installed on your iPhone.
Based on the details provided by RipDev on their website; it looks like they are trying to address one of the problems.
didn’t want to re-install all those “not from the App Store” apps,
InstallerApp is exactly what you need. Synchronize all applications
between your iPhone and computer, install the new firmware and
synchronize all the apps again back to the phone — no more painful
downloads and installation directly on the iPhone.
So this means that after you have updated your jailbroken iPhone with the latest firmware update and have jailbroken it again, you won't have to re-install the apps one by one using either Cydia or Installer app as InstallerApp will synchronize the jailbreak apps for you. Though I'm not sure if it also syncs application specific data like iTunes does for iPhone apps from the App Store.
InstallerApp supports only 1st gen iPhone and iPhone 3G and currently works only on Intel based Macs, requires OS X 10.5 or higher, and costs $7 which includes email support for one-year. RipDev have mentioned that they will be releasing a Windows version soon.
I haven't tried it out yet but if it works as advertised, it could solve one of the biggest annoyance while updating a jailbroken iPhone with the latest firmware.
What do you think?