Okay, so skillshot heals are a "probably not". How about channeled heals?
Was starting up a replay of SC2 Wings of Liberty, and thought to myself "League presently doesn't have any channel-type healers outside of
", though Janna's ult is not really meant to be used for patch jobs because of its long cooldown and reliance on AP to have real potency.
Besides, I was more thinking along the lines of the above Heroes of the Storm character, Lt. Morales. She has a channeled heal that she can keep going on an ally even while moving, though it's not strong enough to keep an ally alive if they're focused in a team fight, and she has to stay close to said ally to keep the channel from breaking.
While Riot might say "Soraka does this well enough", burst heals are different from channeled heals. A long time ago, Riot said that heal-ally-over-time effects were bad gameplay, but is that still the current opinion?
kappa