The previous information page about the app ”Grid Tool” is now obsolete and has been removed.
Unfortunately, the app is currently (17 Feb. 2016) suffering from some bugs. The time plan for correcting these bugs is very unclear.

If you search an app that will tell you your coordinates in the UTM grid, the app UTM Position Mailer is recommended instead.

For the time being, these old sub pages are left as they are: