And it's not going anywhere.

Photo: Getty Images / Westend61

Self-care: a noun, a verb, a state of being. This wellness-minded notion, and the fact that we should all be practicing more of it, really came to the forefront toward the end of last year. In fact, more than half of millennial women made self-care their 2018 New Year's resolution-essentially agreeing that mental health deserves more attention and committing to make it a top priority.

And if you still think self-care is a "trend," nope. It held strong throughout 2018 and shows no signs of slowing down. The proof is in the downloads: Apple just released a best of 2018 list and self-care was the app trend of the year.

The top-rated self-care apps, according to Apple, included sleep and meditation app Calm (which was also Apple's app of the year in 2017). Another popular pick was 10% Happier, an app based on the New York Times bestselling book providing daily videos and weekly guided meditations to help even meditation skeptics lead happier lives. There was also Shine-a self-care and meditation app providing daily motivation texts and five-minute affirmations to guide you through everything from toxic friendships to self-care in the online dating world.

Interestingly, while self-care and mental health apps clearly blew up this year, both Apple and Google also introduced features to encourage users to spend less time on their phones in the name of mental well-being. Google's Digital Wellbeing and Apple's Screen Time both allow users to track how many minutes they're spending on their phones and in specific apps and provide tools aimed at helping you limit time spent on your device so you can disconnect and be more present in other areas of your life. (Related: I Tried the New Apple Screen Time Tools to Cut Back On Social Media)

While the idea of self-care was certainly around last year too, it truly exploded this year, permeating multiple industries. More gyms began to incorporate mindfulness into their programming, offering guided meditations, foam rolling, trigger point release sessions, and other restorative options aimed at providing a more balanced approach to overall well-being. Earlier this year, ClassPass introduced programming that focused on wellness and self-care. And when legacy weight-loss brand Weight Watchers rebranded this fall as WW, ("wellness that works") they partnered with popular meditation app Headspace-noting that mental health is a huge part of reaching any fitness or weight-loss goal. (Related: Headspace Launched a Podcast-Meets-Meditation Designed to Help You Sleep)

The beauty industry was another natural fit for the self-care movement. Brands were quick to jump on the idea as the new "treat yo self," encouraging women to go ahead and take that bubble bath while wearing a sheet mask and drinking a glass of wine as a way to de-stress and carve time out for yourself in an otherwise hectic grind. (Related: How to Make Time for Self-Care When You Have None)

Celebrities also amplified the importance of self-care by posting their advice on International Self-Care Day. (Yes, that's a real "holiday" that's actually been a thing since 2011 to promote the overall benefits of self-care on a daily basis.) They reminded people that self-care is also about listening to your body and what it needs-whether that means prioritizing sleep and meditation, sweating, or just canceling plans and giving yourself permission to do nothing.

Essentially, as a meme shared by Viola Davis expressed, self-care isn't just one thing-and it's definitely not just about booking a pricey boutique fitness class or spa treatment. Self-care can also mean going for a walk to get some fresh air, or finally booking that doctor's appointment you've been putting off forever.

So while we're glad it was a trend in 2018 (FYI there are now more than 10 million posts on Instagram with #selfcare) we hardly classify it in the same category as Jazzercise or the juice-everything-frenzy of past years. Because, at its core, self-care is really just about taking ownership of your mental and physical well-being-and that's something we should all prioritize every year, bubble bath included or not.