looking for software to find by (and change) image extensions in bulk.

(SOLVED)

I'm looking for a program that can find image files by their extension, within multiple folders then take those files and change their extensions and either return them to their origin folder or place them into an output folder. a program with a GUI would be greatly appreciated as command line drives me up the wall.

the extension i need to convert is .jfif (thanks twitter) to .jpg

Bonus points to anyone that can sugest a good program for converting .webp images to either .PNG or .jpg in bulk.

Thanks in advance to those who answer.