Thanks pclin, that works! 
If anyone is interested, I use this to toggle the LEDs. I use this bash script:
Bash
#!/bin/bash
# Toggle state of hyperion LEDs
LED=$(~/hyperion/bin/hyperion-remote -l | grep LEDDEVICE -B 1 | grep true | cut -d: -f2 | cut -d, -f1)
if [ $LED = 'true' ] ; then
~/hyperion/bin/hyperion-remote --disable LEDDEVICE
echo Turning LEDs OFF!
else
~/hyperion/bin/hyperion-remote --enable LEDDEVICE
echo Turning LEDs ON!
fiI can invoke this with my phone using e.g. the app RasPi Check.
I also created a submenu (Amber skin) to invoke: System.Exec(/storage/.hyperion/blinkenlights_toggle.sh).
Paths need to be adjusted, of course.
[I can't find a way to mark this thread "Solved". If an admin be so kind, thanks!]
