You are downloading the Dev Center Essentials AppX file v22.214.171.124 for Windows Phone. Dev Center Essentials is a free and useful Productivity app: Get information on how your apps are doing, both Windows and Windows Phone apps.- Payouts: summary, proceeds per IAP- Reviews: view, ... You can now download the offline AppX file to install & try it.
Download Locations for Dev Center Essentials 126.96.36.199 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 Dev Center Essentials AppX file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.