The Facebook personal assistant. You can ask it to do almost anything. And it does it! I've gotten it to do a lot of work for me and help me through daily tasks.
Much better experience for me than texting. Light weight on desktop and amazing integrations (Gifs, stickers, even audio and video).
I rarely read things when I see them anymore. I use Pocket to save it all for reading in one gulp. Saves me time and I learn a lot more.
The #1 social network I use now. Lots of entertaining stuff and houses the tech community. I learn quick bullets there and find funny stuff. I even get great news and article suggestions
Syncs all my photos (stores them for FREE) and does cool stuff with them too! You can search by faces, categorize, make collages, and it'll automatically create and touch up pictures for you.
The meditation app. Very simple app, but very very impactful.
You can set triggers and automate some of the things you do in life! Browse some recipes and see if you find anything useful. I'm using quite a few!
Super simple note-taking. I keep lists and more on Keep.
Work communication. I imagine most startups are on it, but if you want a great productivity/team collaboration weapon, this is it.
I love podcasts. Every day when I'm cooking or walking, I'm listening to a podcast.