You are downloading the 6snap XAP file v220.127.116.11 for Windows Phone. 6snap is a free and useful Social app: 6snap is the first full featured snapchat app for Windows Phone. Snap a photo or a video, add a caption, and send it to ... You can now download the offline XAP file to install & try it.
Download Locations for 6snap 18.104.22.168 XAP file
To try to install it manually from an SD card, you should choose one of the server location above to get the offline 6snap XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.