@GT yes, perfect: thanks!

Hi all!
how I can add an app to the lateral bar?
thanks
Paolo

Same problem, I solve with this (https://devices.ubports.com/#/cooler

Install using system-image server
NOTE: This will wipe your device! Please back up all valuable data.

1. Install the required tools:

sudo apt-get install ubuntu-device-flash phablet-tools
2. Reboot your device into fastboot mode and Connect your device with an USB cable to your computer.

3. Download adb unlocked recovery: http://cdimage.ubports.com/devices/recovery-cooler.img

wget http://cdimage.ubports.com/devices/recovery-cooler.img
4. Flash your device using this command: (NOTE! This will wipe your phone!)

sudo ubuntu-device-flash --server=http://system-image.ubports.com touch --device=cooler
--channel=15.04/stable --bootstrap --recovery-image=recovery-cooler.img