What was the most influential piece of software in the 2010s

Chrome?

Browser-driven web development is eating a lot of domains and Google is the forcing function through Chrome. For better or worse, it's been incredibly influential.

Docker and the rise of containers as a big deal also seems to qualify with Kubernetes blowing up towards the end of the decade.

NodeJS definitely ushered in a new wave. A lot of developers are learning Node as their first thing and "full stack JavaScript" as a default in a lot of cases.

React was definitely the most influential library in frontend web dev.

Android

(it was release in 2008, but took off in 2010's)

Odds are what-ever is in your pocket right now uses it.
Most of the world is connected by it.
It is the operating system most used to connect to the internet

If the 2010's is remembered as when the web really started to "explode", then it could be said Android was the OS that powered that entire explosion.

(I took all my info from wikipedia, sorry haha)

(((Clojure.))), I think.

Although Clojure was officially released a few years out of bounds (2007), the stable release > w/ complete Java-interoperability (w/ Protocols) came months before 2010.

All of this decade's influential contributions in full/JAM-stack web development frankensteins several ancient yet seemingly future-proof paradigms and ideas from Functional Programming, agent-agnostic architecture, platform-agnostic development, and more fundamentally, lambda calculus (the standard notation for defining pure discrete mathematical functions or Functors I believe this evolutionary resilience towards concurrent-threadings simple but disastrous pitfalls (like all of the rules for state management :P ) can be traced to Rich Hickey's rediscovered intentions and potential in LiSP and later Clojure.

Before deliberating the sanity of my beliefs any further, it's apparent to me for example that the beloved features and philosophies stuffed into React are precisely the inherent inexhaustible abilities in a prefix-notation syntax like LiSP, which is precisely why Hickey took initiative in 2005 to begin integrating the already retrograde shared-state loosely object-oriented roots in Java/JavaScript with a meta-abstracted and expressive functional development environment.

I may be over-possessed with Koolaid from the Clojure camp I've squatted in but as a Clojurist, when much of the internets hoopla surrounds some newborn lambda-fn feature or module is released in cluNkY JavaScript, the origins for its newfound practical use in modern web-development is deemed irrelevant, and I feel befuddled - what's the big deal? comes to mind, and seek new opinions.

Docker and TensorFlow immediately come to mind.

Python by a long shot.

I think Android OS as it altogether changed the landscape of mobile app development. In terms of corporate, I think evolution of startups is another big thing. And ultimately the tech they developed has influenced people directly and indirectly.

I'm not sure it's up there with the other answers right now, but Bitcoin and to an extent all cryptocurrencies.
I think that while technologies will come and go, changing the paradigm for banking is something that's going to have a profound effect over the next few decades.

Google Analytics (and by extension other web analytics tools) - A free and easy way for developers, webmasters and product managers to get quick feedback on the usage of their websites and apps. Data helped focus developers' attention on solving real user problems.

True, GA was around since the mid naughties, but it really gained traction in the 2010s. And now it supports some of the world's largest sites.

I'm going to be a little creative here and force rank by impact and period of influence...

• Chrome (maximum points in both areas)
• Docker (maximum impact points, close to maximum on period)
• NodeJS (maximum period points, high impact)
• TypeScript (moderate scores for both)
• ... and finally, Rust (low period, high impact, and interest is surging... this is one to watch)

IDE: Visual Studio Code
Front End Framework: React
Programming Language: Kotlin