If you are on a Windows Insider on the Fast Ring, then you are running a Redstone Build (14xxx).
Microsoft has released a pretty big update for the Windows 10 Store app. This update, v11604.1000.21.0 introduces a new and redesigned store app.
The update is apparently also available for Insiders on the Release Preview Ring as well.
However, some users have experienced difficulty updating to the new store app. The update isnt available for some while others who do get the update are getting 0x80073CF3 error while trying to install it.
Let us know if you have successfully installed the update and if any, what workarounds you used.