Apple - Change the location of an icon in the menu bar?

If a menu icon is allowed to move, command + mouse select will work.

You might have to patch the program (or System Ui Server). Have you asked the developer if they can implement this as a feature?

Only the Apple icons are movable on my 10.6.7 systems so it certainly isn't easy for a developer to get this working and may be impossible in practice.

The only workaround would be to have a script that delays the radium start as the leftmost item is the last to load. If you had a launch script that slept for 3 minutes and then killed, relaunched that app - it would be leftmost until another started... If it was really important, you could kill and relaunch it periodically every X minutes to ensure that over time it's the leftmost icon without you taking manual action.

While not a free option, the 1.0 release of Bartender allows you to move any menu bar item around, including system items such as the clock, notification center, and the battery indicator.

I'm not a fan of adding more clutter (i.e. use extra apps) to de-clutter or organize something + most of solutions do not work well in EL Capitan. My personal annoyance was Fantastical icon separated from clock. What I found is that menubar icons order loosely follows respective app launching order, i.e. first launched app takes right-most spot, next to OS X system icons space.

All I had to do is re-arrage login items order and menubar icons got in their desired places. OS X system icons (clock, wifi, battery) still can be re-arranged using CMD-drag.

p.s. to re-arrange login items you'd have to delete and re-add them. No biggie, just Apple-way of doing things lately :)