How to open .EXTRA file extension?

If you cannot open a new file that has been saved in the .EXTRA format you need to download the appropriate software. The manufacturer of .EXTRA files is Google; .EXTRA files belong to the Misc Files category. After downloading the application from the list available on our website just run an unknown file, and as the default set the newly installed application supporting the .EXTRA files. Activities performed in the order described should solve the problems with all the files in the .EXTRA format.

• What is .EXTRA file?
• How to open .EXTRA file?
• What is .EXTRA file?