Users can travel to other possible worlds that can or could've happened from the endless abyss of alternate outcomes and continuities, being able to taste how dissimilar those probable worlds are to their own. Consequently, one might take interest in one or a couple worlds and may create a permanent stay.
Though while it be restricted to the context of the story, possible futures, pasts, and even present events withhold endless amounts of variety in spite of how distant or close it is to the original line of events, and users will inevitably find horrors, pleasures, joy, and sadness that could have been and still can unfold.
Phineas, Ferb and Dr. Heinz Doofenshmirtz (Phineas and Ferb the Movie: Across the 2nd Dimension) use Other-Dimension-Inator to open a portal to an alternative world.
With Bill Evil's Inter-Dimensional Transporter Henry and the other main characters can travel to other dimensions of the multiverse.
The Infinite Forest (Destiny) allows the Vex to travel to an infinite number of expanding realities.
Mastemon (Digimon) can freely open portals to other realities.
Funny Valentine (Jojo's Bizarre Adventure Part 7 Steel Ball Run) has the ability to hop/travel to nearby dimensions by making them coexist in the same dimension when in between 2 objects through his stand Dirty Deeds Done Dirt Cheap…
…Enabling him to bring in several different dimensional counterparts of himself and others (D4C protects him while the counter parts of other people/objects will merge and collapse in on themselves on contact), be able to transfer his Stand to another one of his counterparts and turn objects/people into portals for the nearby dimensions.
Dream Phantom (Valkyrie Crusade) can travel to other worlds through books.
Twilight Sparkle (My Little Pony Equestria Girls) going through the Crystal Mirror to an alternative world.
Penn Zero (Penn Zero: Part-Time Hero)
Serge (Chrono Cross) can travel to parallel version of his own world via the power of the Astral Amulet.
Stewie's (Family Guy) device allow them to travel multiverse.
Wormhole, A.K.A. Experiment 272 (Stitch!)
The Phase Oscillator (Batman: The Brave and the Bold) is a device created by the Red Hood of Earth-23 that can open temporary wormholes, allowing its owner to travel to several alternate realities.