Images transfer from a website to an app and organising them

I need to get quite a few images off a website...i.e download them (ie. right click save) then post/upload them onto an app perhaps with a few word descriptions for each image. They need to be arranged/grouped into their correct technical named group. However all of this without reference to their names on the website (I.e I need to change each image's name reference on the website to a new one on the app, however I still need to cross reference back to the website to get the name of that image when needed. Easily Also without mentioning the original name reference of the website image on the app). The other part is I need to be able to then cross reference back to the website and finding that image easily again without searching through the whole website for a chosen image, in order to pick up the correct code/name for ordering purposes. Its an easy unskilled mundane job but just the cross referencing needs a bit of thought and a convenient solution prior to doing the job.