Many people who had routines disappear from the app yesterday have gotten then back by now without having to do anything except log out of the app and log back in again. but not everyone has them back yet. But that only applies to the routines that disappeared all together at one time yesterday.
Other SmartApps may have disappeared over the last few week as part of the Groovy shut down and those might indeed need to be re-created individually. For those cases, see the link I just gave you:
Why Did My Integration/SmartApp Stop Working in January 2023?