You are downloading the ChatUp APPX file v2015.227.1830.3765 for Windows Phone. ChatUp is a free and useful Social app: Talk to random people all around the globe with ChatUp! No need for signing up for an account as you use a name that will only be available ... You can now download the offline APPX file to install & try it.
Download Locations for ChatUp 2015.227.1830.3765 APPX file
Important Notice: Now Due To Unspecified Limitations, You Can Not Use The Offline APPX 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 ChatUp APPX file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.