They should really put the class that the spell can be used by, in the spell description when doing UA. it makes for much easier reference.
Spells:
Acid Stream
This is nifty! A level 1 line spell that gives draconic sorcerers a bone. Most importantly, it's not necessarily useful for damage, because generally speaking having a lot of your enemies use up their action to scrape the burning acid off their bodies helps your party win the Action Economy war. And if they decide to just tank the damage, it's orders of magnitude better than Witch Bolt.
Otherworldly Form
A way more functional buff than Tenser's Transformation, especially for Clerics. (Seriously, it takes 10 min just to put on heavy armor!)
Spirit Shroud.
A short duration (and short range) super-hex with damage boost that scales with spell slot, that Clerics, and Eldritch Knights can access! Niche appeal, but the niche is real, and they will be thankful for it.
A Forward on the The Summoning Spells: A quote from me about how I would change the summoning type spells;
Every Single Pet (summoning or animating) Spell gets a specific stat block, a limited list of actions, and a hard cap of one thing at a time. Ala the Battlesmith (and the UA class Variants Ranger)
I wrote that on my birthday, so I will egotistically interpret that to mean these were a gift to me, thanks!
I will also note that picking one of three different types of generic monsters is a better compromise than what I was thinking of at the time, so extra kudos for that. Also, in general, having a monster get more buff as you up cast the spell is a more DM-friendly option than getting more monsters.
One nitpick about them all: There is no HD listed. I think the HD mechanic on monsters is mostly vestigial, but there are a few abilities and spells that still interact with them for some reason, so it would be a good idea to list something there.
Summon Aberrant Spirit
Slaadi are from the far realm now? I guess that works.
Summon Bestial Spirit
Comes with an Aquatic beast option, unlike the Class Variant Ranger (which should totally get one). Though it is questionable how you might be able to issue a verbal command while underwater.
Summon Celestial Spirit
Only has two options, but both come with healing, so that's nice I suppose. Extra noteworthy is it's large size, meaning you might be able to convince your DM to give you a flying mount when you cast this.
Summon Elemental Spirit
It's one of the classic four elementals, what more do you want?
Summon Fey Spirit
This is where the summons get interesting. Sure, the fey spirits can stab things with a sword, but they also teleport around and cause an effect while they do so, which sets this spell apart from it's (non-celestial) cousins which are mostly divided up into combat roles and/or terrain types.
Summon Fiendish Spirit
The Highest level of the Summoned Spirits, and as such it's a bit underwhelming due to the slightly mundane options of brute/skirmisher/archer with an emphasis on being tanky. There are some quirks (like Devil's Sight) but they seem a little light. Of note, no Succubus/Incubus, which would be nifty for a control option. At least it is another large spirit, so there might be an option to ride it.
Summon Shadow Spirit
In contrast, this spirit is inherently a controller, which can get some stealth for extra spooky goodness.
Summon Undead Spirit
Now for arguably the most creative of the lot. This spirit has oodles of potential. Except for the Skeletal option, which is just a no-frills archer. Give the Skeleton some love~
Magic Tattoos
A new magic item that shares cribs from the shared attunement slot gimmick that prosthetic have. While incorporating a new gimmick where size=rarity. Also apparently they are transmitted via magic needles, which somehow magically reappear when you loose your attunement. Unfortunately you need skin to make the tattoos work, which is a problem for some races.
Absorbing Tattoo
Are you tired of your bear totem barbarian taking full damage from psionic attacks all the time? Well we have just the look for you! Also lets you eat the elemental damage once per day to regain some HP, which is an underexplored mechanic.
Barrier Tattoo
It's armor in your skin, without having to actually use armor, or even have proficiency in it. Particularly useful for Druids.
Coiling Grasp Tattoo
Well, it's significantly better than a net. Still wouldn't rely on it for long.
Eldritch Claw Tattoo
Great for Monks (because there isn't much of anything outside of that one adventure to enhance unarmed strikes), but it won't work for Beast Barbarians (from a Previous UA). Requiring a Bonus Action to use is a bit of a bummer, as Monks really want to Flurry for maximum use of the tattoo.
Blood Fury Tattoo
Well that's certainly Legendary. It's basically a Paladin Subclass Capstone as an always-on item.
Illuminator’s Tattoo
Lifewell Tattoo
Relentless Endurance and necrotic resistance for everyone!
Ghost Step Tattoo
At first glance, it sounds really good: You can phase through objects and people like a ghost for a turn as a bonus action. Then you realize that it doesn't say your carried equipment also becomes incorporeal...
Masquerade Tattoo
The trendiest of fashionistas demand a tattoo that changes with their whims. Also lets you disguise self once per day, but really that's a minor benefit in comparison.
Spellwrought Tattoo
Take a spell scroll, embed it into your skin, and cast it even if it isn't on your spell list. And best of all it doesn't even require an attunement slot!
Shadowfell Brand Tattoo
Permanent advantage on stealth checks, and once per day you gain resistance to a single source of damage. It's Very Rare, which I suppose makes sense if you don't consider rarity to have a direct correlation to power.