Ok so on Galaxy of Heroes I'm making an all droid team. Or at least mostly droids. Anyway I'm wondering, is there any droids that can heal allies?
No, currently there is not. However, there is a healer with droid synergies — Jawa Engineer. He can be farmed from the Guild Shop and I've also seen him in the Shard Shop occasionally.
Edit: See the other answer for details on BB-8! He is best used with Resistance teams, but can certainly be used with other Droids.
BB-8 has two abilities that heal Droids
Illuminated Destiny: Dispel all debuffs on all allies and Expose all enemies for 2 turns. All allies gain 80% Turn Meter and gain Advantage, Critical Chance Up, Critical Damage Up, Offense Up, and Speed Up for 4 turns. Droid and Resistance allies recover 20% Protection. This ability starts on cooldown and can't be Evaded. Whenever a Droid ally scores a Critical Hit, reduce the cooldown of this ability by 1
Self-Preservation Protocols: When BB-8 takes damage he has a 50% chance to gain Foresight for 2 turns. At the start of each encounter, if BB-8 is active, Droid allies gain 8% Turn Meter for each active Droid ally. When BB-8 Evades, Droid allies recover 8% Health and 8% Protection.