[The Best Apps You've Never Heard of] Sentimental Sugarcube:
Oh boy, I've been searching for a question like this for a few days now! I hope XDA doesn't mind if I repost this question, when I decide to. Anyway, the list of the best apps on my device are all from the Play Store, though.

Brave Private Web Browser | It's private, fast, efficient, and blocks all ads & trackers.

https://play.google.com/store/apps/details?id=com.brave.browser

Boost for reddit | It loads faster, doesn't crash as much, has advanced functions, and is way more customizable than the official Reddit app.

https://play.google.com/store/apps/details?id=com.rubenmayayo.reddit

CocoCam (by MagicDmStudio) | It has cute, aesthetic stickers, frames, and filters — it reminds me of PicsArt in some ways, but it's way simpler and is much more affordable.

https://play.google.com/store/apps/details?id=com.imendon.cococam

Collage Maker (by Grit Inc.) | I tested out 8 free/nearly free collage maker apps, and this one was the one — free (contains minimal ads), simple, easy to use, and is the best alternative to GridArt!

https://play.google.com/store/apps/details?id=com.binghuo.photogrid.collagemaker

Daylio Journal - Mood Tracker | It's an excellent mood, activity, habit, and pattern tracking app — it's incredibly thorough with its advanced statistics, and is very customizable.

https://play.google.com/store/apps/details?id=net.daylio

Flo Ovulation & Period Tracker | I honestly don't even use any of the other functions besides tracking just my period, but it's really important and I've been keeping track of it since 2017 now.

https://play.google.com/store/apps/details?id=org.iggymedia.periodtracker

GoodRx: Prescription Coupons | It brings down the cost of my medications by a highly significant percentage, and has a new feature called "GoodRx Rewards" in which you can earn points for coupons!

https://play.google.com/store/apps/details?id=com.goodrx

Google Keep - Notes and Lists | It's simple (although it can sometimes be too simple), appealing to the eyes, and does just what I need it to do.

https://play.google.com/store/apps/details?id=com.google.android.keep

Google Voice | It's basically a burner number that's linked to your Google account — except, it's completely free.

https://play.google.com/store/apps/details?id=com.google.android.apps.googlevoice

Life360: Find Family & Friends | It enables you and others to always share each other's live locations, battery percentages, and more. Even with just the free version, it's worth having.

https://play.google.com/store/apps/details?id=com.life360.android.safetymapd

Messages (by Google LLC) | It has a better appearance, functionality, and is much more organized than my default messaging app (which is Samsung Messages).

https://play.google.com/store/apps/details?id=com.google.android.apps.messaging

Quora — Ask Questions, Get Answers | It's somewhat different compared to other (universal) internet forums, like Reddit or 4chan — for the information I tend to read about, I'm able to find what I need on there.

https://play.google.com/store/apps/details?id=com.quora.android

Samsung Members | It's mostly boredom that keeps dragging me back to Samsung Members.

https://play.google.com/store/apps/details?id=com.samsung.android.voc

Samsung Wallet (Samsung Pay)| I love being able to pay and use membership cards without needing my physical card. Plus, it looks kind of cooler paying with your phone than a card, lol.

https://play.google.com/store/apps/details?id=com.samsung.android.spay

Spotify: Music & Podcasts | Compared to other music streaming apps I've used, such as Pandora and TIDAL, this has been the most convenient one I've had.

https://play.google.com/store/apps/details?id=com.spotify.music

Telegram | I use it for the privacy, mainly, and it's served its sought-out purpose, so far.

https://play.google.com/store/apps/details?id=com.spotify.music

TextNow: Call + Text Unlimited | It's the best burner number app, in comparison to Text Free, Burner, and Sideline, in my opinion. It does have a lot of ads, so be prepared to have an ad blocker ready.

https://play.google.com/store/apps/details?id=com.enflick.android.TextNow

Whisper | "Share confessions, thoughts, and stay anonymous (or not); see posts locally and worldwide!" The app's gone to ****, to be honest, but I'm probably always going to have a Whisper addiction.

https://play.google.com/store/apps/details?id=sh.whisper

P.S. I do have one best app I downloaded outside of the Play Store; it's called Package Disabler Pro, and it's used to disable bloatware without needing to root your device.