My Minecraft Pocket Edition 10-Year Anniversary
Exactly a decade ago to this day, on November 27, 2015, I finally purchased (what was at the time called) Minecraft: Pocket Edition on my own iPad.
Prior to this my only personal experience with Minecraft was playing the 1.8 demo in my sister's MacBook, which was free, but you could only play for a few hours and only in a set Survival world, and you couldn't change the gamemode or enter any other maps.
But then that day I finally convinced my mom to get me the full Pocket Edition on my own device, allowing me to finally be able to play whenever I wanted to!

Pictured at the top of this entry was the very first screenshot of Minecraft I took, which was of the menu screen. Yes, it used to look like this.
The version I started playing in was v0.13.0 alpha. This was the version that added the proper Nether, meaning I never actually managed to see the Nether Reactor Core, and although its functionality was removed, the Original Stonecutter was still available in the creative menu.
At the time I didn't know that Minecraft: Pocket Edition (or MCPE for short) was very different from the Java version, which back then was basically the universal standard. A lot of items and features I was looking forward to using weren't in MCPE yet, including stained glass, prismarine blocks, pistons, and a lot of stuff which was super vital, but I lived without.
I just looked up the update on the Minecraft Wiki, and these are the items that were added in 0.13 alpha, which I wouldn't even imagine not having.

(Note, those are the newer textures of the items, for some reason ¯\_(ツ)_/¯)
I wasn't really much of a Survival person, and although I am more into it now, I've always been more of a Creative Mode player, and this was the case since the start. Something silly, though, was that in MCPE you could change from Survival to Creative (and vice-versa) completely freely, and this lead to one of the first worlds I created, and one I wanna highlight.
I don't remember the seed, or the name I had for it (probably "Materials World" or something lol), but in it I basically made a base inside of a hill, and made separate rooms each filled with tonnes of all mineral blocks (Coal, Iron, Redstone, Lapis Lazuli, Emerald, Gold, and Diamond), which I would then mine in Survival and get super rich from! Though I never built anything else in it, I think.
I did this because your inventory reset when you switched from Creative to Survival, so this is what I did to get all of those items.
I am 99% sure that the idea for this world was inspired by the classic "Spider Encounter" sketch by Slamacow, which for some reason isn't available on YouTube anymore, but I found an archive of it.
I am pretty sure the following screenshots are from that world, given my inventory's contents and the long hall with the doors leading to the mineral rooms.
The first image of the baby cow in the hall is from January 2, 2016, and the three inventory images were taken on December 23, 2015.

The only other world I wanna highlight is the one I most vividly remember, which was a creative superflat world I named "Decorations".
This was a world where I built whatever I wanted, and I just built everything in a straight line, simply in whatever order I happened to build them. Here I made random stuff out of curiosity, tried to recreate things I saw in videos, and just did whatever cool things I thought of in the capabilities of Creative Mode at the time!
This is a world I remember super fondly. Pictured below are some of the things I made in it that I took screenshots of:
What I thought was a Menger Sponge, and a Diamond Tree inspired by carykh videos; a small obstacle course, a rollercoaster inspired by the Minecraft Handbooks, some random paintings next to a giant Emerald Ore from TSMC, a random very small house, and some other miscellaneous stuff behind a Skeleton in full Leather armour.
These images range from December 2015 to May 2016.

You might have noticed that I am talking about these worlds in the past tense. Well, I forget the exact date, but around Summer 2016 I accidentally deleted the Minecraft app off my iPad, resulting in every single one of these worlds being lost from existence.
Although the loss of these relics occasionally haunts me, I still have all of these screenshots to keep the memories! Which I am super glad to be sharing with you on this wonderful anniversary.
Minecraft: Pocket Edition allowed me to create so many cool things, and is probably one of the games I played the most of in my entire life, and although all of these worlds are gone and I've switched to playing only Java, I am still glad I have these memories. :)