You are downloading the Irssi Notifier XAP file v220.127.116.11 for Windows Phone. Irssi Notifier is a free and useful Social app: Windows Phone 7 phones already have support for several social media services. Irssi Notifier provides this support also for ursers of Irssi IRC ... You can now download the offline XAP file to install & try it.
Download Locations for Irssi Notifier 18.104.22.168 XAP file
Note: To install it manually from an SD card, you should choose one of the server location above to get the offline Irssi Notifier XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.