With the amount of customization available, the sidebar should be more integrated into the webpage. First, in the space between the opera symbol and the applications, add a simple arrow to hide and show the sidebar instead of going into settings every time. Next, add an option to make it more hidden/seamless through appearance changes. Adding an opacity % slider where the background color becomes increasingly transparent and shows the webpage or theme behind it would be the main option. Finally, I understand the purpose of sorting the apps by categories with a line (_) for simplicity, but why is there not an option for the user to sort it themselves and remove the lines altogether? I feel like if these options were available, I would use the sidebar.