You are downloading the Modern Gitter AppXBundle file v2015.1127.2149.0 for Windows Phone. Modern Gitter is a free and useful Social app: This is a non official client app for Gitter.The app contains features like :* current list of rooms* chat messages in realtime ... You can now download the offline AppXBundle file to install & try it.
Download Locations for Modern Gitter 2015.1127.2149.0 AppXBundle file
Important Notice: Now Due To Unspecified Limitations, You Can Not Use The Offline AppXBundle File To Install It Any More.
To try to install it manually from an SD card, you should choose one of the server location above to get the offline Modern Gitter AppXBundle file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.