Well, that kind of animation is very easy to implement without any framework or library at all. All you have to do is pre-cache the sprites, then create visible sprite objects and have them cross the screen. You can resize them while they do so.

Pseudocode:

let reactions = array of Reaction

// on one thread, do the networking and handle new reactions
loop {
  let reaction_type: ReactionType = get_reaction()
  if (reaction_type) {
    let reaction = new Reaction(reaction_type)

    reaction.position.x = screen.width
    reaction.position.y = screen.height - screen.height / 2 + random
    reaction.initial_position = reaction.position

    reaction.size = Size(1,1)
    reaction.initial_size = reaction.size

    reactions.add(reaction)
  }
}

// on another thread, do the animations
loop {
  foreach (reaction in reactions) {
    reaction.position.x -= 1
    reaction.position.y = reaction.initial_size + sin(screen.width - reaction.position.x)
    reaction.size = reaction.initial_size + sin(screen.width - reaction.position.x)

    if (reaction.position.x == -reaction.size.y)
      reactions.remove(reaction)
    else
      reaction.render()
  }
}

// ideally, do user interaction on yet another thread or the main thread

You can change the formulas to your liking. Unfortunately, I am not an iOS developer, so I do not know how to implement it.

You might want to check this :

Reactions is a fully customizable control to give people more ways to share their reaction in a quick and easy way. http://cocoadocs.org/docsets/Reactions/1.1.1/