Startup Disk Creator is described as '(usb-creator) is an official tool to create Live USBs of Ubuntu from the Live CD or from an ISO image. The tool is included by default in all releases after Ubuntu 8.04' and is an app in the OS & Utilities category. There are eight alternatives to Startup Disk Creator for a variety of platforms, including Windows, PortableApps.com, Linux, Android and Android Tablet. The best alternative is Rufus, which is both free and Open Source. Other great apps like Startup Disk Creator are Ventoy (Free, Open Source), UNetbootin (Free, Open Source), YUMI (Free, Open Source) and Universal USB Installer (Free, Open Source).
Ventoy is an open source tool to create bootable USB drive for ISO files. With ventoy, you don't need to format the disk again and again, you just need to copy the iso file to the USB drive and boot it.
YUMI (Your Universal Multiboot Installer), is the successor to our MultibootISOs. It can be used to create a Multiboot Bootable USB Flash Drive containing multiple operating systems, antivirus utilities, disc cloning, diagnostic tools, and more.
DriveDroid allows you to boot your PC from ISO/IMG files stored on your phone. This is ideal for trying Linux distributions or always having a rescue-system on the go... without the need to burn different CDs or USB pendrives.
WinUSB - simple, portable and lightweight tool, lets you create multiple Windows bootable USB flash drive using ISOs or DVDs. Formatting drive is not required when free space is enough. Boot with NTFS flash drive in UEFI system supported for most PC.
Automatically make a live bootable usb with ease with AutoBootDisk, a open-source program Features Automatic Updates Automatic Downloader with 78 Linux Distributions Supported, and a custom section if you don't find your distribution in the list.