ios will allow an app to set location. There may not be a free app but there are apps being sold.
Before changing locations Watch your permissions. If you have location only while using the app, then you can toggle Pokemon Go off and on by flipping out the app. If you have location always, then you have to sign out of PoGo.
If I sign out of Pokemon Go after a jump, I have to make sure that I wait until the Pokemon Go app closes. I wait until the screen with "returning player" pops up then I close the app. (It can take a long time sometimes for the black screen to resolve. (I think)Your account is attached to the last location until the sign in screen pops up.
I turn off wifi if I spoof and (try to) stay under the radar by not contacting Pokemon Go ever. Spoofing is a big swallower of time so I rarely do it. It can give you the feeling that you are getting out and going places though.
and then there is You are going too fast. If you get this while jumping, power off your phone and hold your breath. I wait between 15 minutes and 2 hours depending on the jump.
One of the sites selling a gps app said that the server keeps 4 months of data for each account.