I am tinkering with a few old computers and have Linux Mint and Pop!_OS distros on two flash drives. When I had the Linux Mint flash drive plugged in to one computer, I installed Gimp and then took it to another computer to open up. I thought Gimp would still be there but it wasn't. Is there a way to keep installed apps on distros on the flash drives? And is there a way to install the added app on a hard drive with the distro? It's no big deal if I can't but just trying to find a way to speed up installs if possible.