This app was mentioned in 15 comments, with an average of 1.67 upvotes
The best Android one I've tried is Decked Builder.
MTG Familiar doesn't have a deckbuilder but it does everything else and I find myself using it a lot more than Decked Builder.
You can use deckedbuilder (App for iOS and Android).
https://play.google.com/store/apps/details?id=com.deckedbuilder.deckedbuilder&hl=de
It lets you manage a collection. You can then create a dummy decklist with all the lands and sort by "collection" and it will seperate the decklist into owned and not owned. It costs a bit but is the most convenient app for deck building I have tested so far.
You can also use e.g. deckedbuilder to manage your deck lists. I don't know, how much those tags cost, but deckedbuilder is something like 3€.
The deck editor in Cockatrice is frankly terrible, I suggest getting the smartphone app Decked Builder (iOS, Android) instead. It will import and export from cloud drives, and you can point Cockatrice at a cloud drive directory to use for decks. Use .dec format to save decks.
Among its many benefits is the simple fact that you can have it open at the same time as a game is going on.
One minor downside - you will need to use Cockatrice's deck editor to correct the display of split cards.
I also wholeheartedly recommend lrcast.com and there is even a subreddit specifically for limited at r/lrcast.
In addition I enjoy mythicspoiler.com as a place where I can look at the whole set laid out in front of me and see the cards next to each other, particularly for each color.
When I'm on the go and I want to learn about new cards, I use the Decked Builder Android app and can do the same thing, sorting by color and then just flip through all the cards. https://play.google.com/store/apps/details?id=com.deckedbuilder.deckedbuilder
This app is particularly useful for the LR set reviews because you can hear them talk about each card and have a reference right in front of you.
Aside from that, watching draft videos or streamers is a great way to learn without having to spend a ton of time/money.
https://play.google.com/store/apps/details?id=com.deckedbuilder.deckedbuilder&hl=en
Been using Decked Builder for years. I can upload my lists to dropbox, or email them directly to myself for future use. Well worth the money. Also, I run BlueStacks app emulator (Free) on my PC so I can use it on my computer if I dont feel like using my phone.
EDIT: I take it back. They just changed their interface and it's shit now. Very upset about this.
I don't keep track of my collection, only my decks. But I use the Decked Builder app on Android to build and keep track of all of my decks. It has a collection tool as well, but I just use it to keep track of a maybe list for each of my decks that are under construction. It's really nice to use and it's extremely convenient if you want to quickly look up a card.
Decked Builder
Decked Builder is the original, and surprisingly, still the best deck builder. Delver Lens is the best for card scanning, collection tracking, and has been adding more deck building features. Forge is the best for play testing. MTG Familiar is the best for trades, rules lookup, and advanced card search.
Decked Builder - Really simple way to build decks and browse through cards. Use it all the time when I need a place to flesh out my ideas.
MTG Familiar - All-in-one solution for all your MTG needs. I primarily use it for pricing, trades, and mana counting, but all the other little functions are great too.
EDHREC - A great resource for Commander deckbuilding, but it is useful for other formats as well. Since the site lists cards that are commonly used with the searched card, it makes it very easy to discover combos and synergies you might have not known.
Card Codex - An insanely helpful tool to discover cards with similar effects. Really great for Commander, but also useful for having 8-of effects in Modern or Legacy.
Scryfall - My preferred MTG search engine. Very clean and well-formatted site, great images of the cards, easy access to prices and alternate art, and some very nice advanced search functions.
MTG Goldfish - Great tool for price checking as it'll give you trends and aggregate pricing off of most online stores and ebay.
Google Drawings - Alright, hear me out on this one. I'm a very visual person and sometimes I like to see all the cards in front of me when I'm building a deck. That's fine when I'm at home and have my cards in front of me, but I have issues when I'm either away from home or still need to buy the cards. Google Drawings lets me drag in the pictures from Scryfall and sort them like I would sort physical cards, which helps me out a lot.
TappedOut - Great online database of decks and where I upload my own. I prefer it over other sites because of the ability to playtest within the site.
Mythic Spoiler - Super useful tool during spoiler season. They upload any of the spoiled or leaked cards directly to their site, complete with translations if needed. They're also very quick, though Reddit is sometimes a bit quicker. ;)
UltraPRO Satin Tower Deck Box - I know it's not a digital tool, but I'd figure I'd include it. As someone that likes to match colors with their deck, sleeves, deckbox, and dice, these have been a godsend. I don't have to worry about digging through my dice bag to find the "correct" colors, I just have to pop the bottom off.
It isn't iOS exclusive??
https://play.google.com/store/apps/details?id=com.deckedbuilder.deckedbuilder
Decked Builder is my go to for deck building and pricing. I bought it a couple of years ago and have been happy with it ever since.
Full: https://play.google.com/store/apps/details?id=com.deckedbuilder.deckedbuilder
Demo: https://play.google.com/store/apps/details?id=com.deckedbuilder.deckedbuilder.demo
There is also an app called MTGBugs that is kind of a news aggregator that unused for a bit, but I use Twitter, YouTube, and Reddit hourly, so it was redundant. Maybe you'll like it.