I updated couple ipads to IOS 9.0.1 and after that can't install in-house apps trough self service. It starts to download, and stops in the middle and gives error stating "Unable to download App". Any help would be appreciated.
Try deleting the Self Service app from the iPad. Then manually update inventory on the device and it should check in and reinstall Self Service. Also, I had to re-tweak our Tomcat & MySQL settings to get it back to performing correctly after the latest Casper update.
You may need to update your JSS to 9.80 to properly manage iOS 9.
Do your in-house apps use a Provisioning profile? There is a new configuration setting 'Allow trusting new enterprise app authors' but after upgrading to 9.80 it is checked for my cfg profiles. However I would have expected it to complain at the beginning not halfway into the download.