Yes, familiar can be used for gaining advantage for allies. From Find Familiar spell description (PHB, p240), emphasis mine: A familiar can't attack, but it can take other actions as normal. Help is listed as one of the actions that could be taken in combat and is a legitimate option for a familiar..
Similarly one may ask, what actions can familiars take?
A familiar can take any action that it is capable of other than the Attack action. This includes the Cast A Spell action, Dash, Disengage, Dodge, Help, Hide, Ready, Search, and Use an Object.
Also Know, can familiars use items? Yes, familiars are creatures and, as such, can attune to magic items so long as they meet the requirements for attunement (For example, the magic item cannot require the attuner to be of a certain class, and the DM must deem the familiar capable of wearing/attuning to the particular piece of equipment).
Similarly, can a familiar use a potion?
A familiar can't attack, but it can take other actions as normal. The only action a familiar can't take is Attack, so if your DM allows a PC to administer a potion with Use An Object, then so can the Familiar. If I'm recalling correctly consuming a potion is using a magic item.
Can familiars stabilize?
"You can use your action to administer first aid to an unconscious creature and attempt to stabilize it, which requires a successful DC 10 Wisdom (Medicine) check." "Your familiar acts independently of you, but it always obeys your commands. A familiar can't Attack, but it can take other actions as normal."
Related Question Answers
Do familiars get their own turn?
In combat, it rolls its own initiative and acts on its own turn. A familiar can't attack, but it can take other actions as normal. A familiar is an independent creature with its own initiative, movement, actions, and so on. So it can take an action, a bonus action, and a reaction.Do familiars get attacks of opportunity?
Yes. Familiars are creatures, and any enemy (assuming it is not in some way incapacitated) can choose to make an opportunity attack against it if the enemy leaves its melee attack range and has a reaction to spend doing so.Does Help Action break invisibility?
The rules on the sprite's invisibility are clear, they only become visible if they attack or cast a spell or lose concentration. Aiding an attack does none of these things, so therefore the sprite does not become visible if they perform this action.Can familiars talk?
However, while many literary familiars are intelligent and capable of speech, 5e's familiars are limited to the intelligence of the shape they take, which is to say animal intelligence. The familiar can communicate with its master, just not verbally.Do familiars need to sleep?
Appearing in an unoccupied space within range, the familiar has the Statistics of the chosen form, though it is a Celestial, fey, or fiend (your choice) instead of a beast.” The rest of the spell doesn't say anything about sleeping or eating. I doubt your familiar will need to eat or sleep, but it depends on your DM.Can Warlock familiars attack?
No, because the familiar didn't necessarily have actions or movement on that turn in the first place - the Pact of the Chain familiar can only attack when the warlock takes the Attack action, which usually happens only on the warlock's turn. A familiar can't attack, but it can take other actions as normal.Can a familiar use a wand 5e?
To use a spell wand, in PHB RAW, the user needs the ability to cast spells. If the familiar is a spellcaster, then sure go for it; otherwise I'd say no. Some wands specifically say, "requires attunement by a spellcaster." While others like the wand of magic missiles, do not require anything.Can familiars use magic items Pathfinder?
All familiars can activate the abilities of their use-activated magic items, so long as these abilities do not require a command word. For more information on these magic item categories, see page 456 of the Pathfinder RPG Core Rulebook.Can familiars use wands?
So the short end of it is "Yes, familiars can use wands. As long as they can hold it in a hand (or whatever passes for a hand for non-humanoids), point it, speak the command word, and succeed at a DC 20 UMD check."Can familiars wear armor?
The stat blocks for imps and quasits don't specify any equipment, so without DM dispensation they aren't proficient. It's also the DM's decision as to whether the imp or quasit can fly while wearing armor. Guiding examples: Sprites can fly while wearing tiny-sized leather armor.Can animals attune to magic items?
If you can get the animal to focus for an hour, yes. From attunement, no restriction is made as long as Animals don't lack the ability to understand so they don't lack the ability to gain intuition.Can a familiar use a ring of spell storing?
The ring of spell storing itself likewise has no restriction beyond requiring attunement, so yes, a familiar can attune to it. The spell uses its normal casting time, range, and duration, and the user of the item must concentrate if the spell requires concentration.How many items can you be attuned to 5e?
An item can be attuned to only one creature at a time, and a creature can be attuned to no more than three magic items at a time. Any attempt to attune to a fourth item fails; the creature must end its attunement to an item first. 
