Hi,
you have to write a udev rules file for the digispark to set the rights for all users to write and read to/from it.
Try the following:
1. Start a terminal
2. Go to /etc/udev/rules.d
3. Create a file as sudo called 50-digispark.rules:
# UDEV Rules for Micronucleus boards including the Digispark.
# This file must be placed at:
#
# /etc/udev/rules.d/49-micronucleus.rules (preferred location)
# or
# /lib/udev/rules.d/49-micronucleus.rules (req'd on some broken systems)
#
# After this file is copied, physically unplug and reconnect the board.
#
# For usage as usb device (5s after connect to usb bus)
SUBSYSTEMS=="usb", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="05df", MODE:="0666"
KERNEL=="ttyACM*", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="05df", MODE:="0666", ENV{ID_MM_DEVICE_IGNORE}="1"
#
# If you share your linux system with other users, or just don't like the
# idea of write permission for everybody, you can replace MODE:="0666" with
# OWNER:="yourusername" to create the device owned by you, or with
# GROUP:="somegroupname" and mange access using standard unix groups.
4. Save file and restart udev service with sudo service udev restart
5. Plug in digispark
6. Start DigiUSB Monitor as normal user (NOT with sudo)
Have fun
P.S.: Don't know why this post looks so ugly