Base Class: Rogue
Trained by circuses, certain temples, and the odd organization of criminals (or vigilantes), the archetypical Acrobat is light on their feet and incredibly agile, able to tumble, somersault, and walk across tightropes with ease. The skills of a gymnast find a myriad of applications in the adventuring world, so whether it be for dungeon diving, cat-burgling, or brawling in a busy tavern, acrobats are always great to have on your side.
Natural Acrobat
Starting at 3rd level, you have proficiency in the Acrobatics skill if you did not already have it, and you have advantage on ability checks made using this skill on your turn. Additionally, you can stand from being prone without using any movement.
Advanced Tumbling
At 3rd level, you can move normally through the space of any creature. Starting at 13th level, once you have moved through a creature's space, that creature has disadvantage on Opportunity Attacks against you until the end of your turn.
Parting Toss
At 9th level, once on each of your turns, immediately after you move out of a creature's reach, you can make a ranged weapon attack with a thrown weapon targeting that creature.
Freerunning
Starting at 13th level, you ignore difficult terrain and climbing no longer halves your movement. Additionally, you can spend up to half your movement speed on your turn climbing even difficult surfaces (such as vertical walls) without making an ability check.
Peerless Dodge
By 17th level, you are so nimble you can dodge almost anything. You have an additional bonus action with which to take the Dodge action. Additionally, when a creature you can see damages you with a spell, you can use your Uncanny Dodge to halve the spell's damage against you.
Super Cool subclass, one thing I would like to note is the wording of peerless dodge. Rogues cannot normally dodge as a Bonus Action so simple adding that to their list of actions that may be done with cunning action would be a simpler way of wording this. There is no need to give the rogue an additional Bonus Action to do this as the other effect of peerless dodge is extremely powerful on its own. Being able to half a spells damage as a reaction is outstanding. A rogue at this level could be subject to a Meteor Swarm and even upon a fail take a maximum of 60 Points of damage factoring in Evasion giving you half damage on a fail. The Upgrade to uncanny dodge should be the highlight to this capstone not the bonus action dodge.
I would also personally change parting shot to disallow sneak attack as being able to do sneak attack on the same turn you take the dodge or dash actions at early levels is very powerful and likely to make DM's trying to run a player with this subclass to cry