You are downloading the Tumblr XAP file v220.127.116.11 for Windows Phone. Tumblr is a free and useful Social app: Post anything, from anywhere. - Find and follow the things you love - Share photos, gifs, video, quotes, chats, links, and ... You can now download the offline XAP file to install & try it.
Download Locations for Tumblr 18.104.22.168 XAP file
Important Notice: Now Due To Unspecified Limitations, You Can Not Use The Offline XAP 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 Tumblr XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.