This is going to be harsh, but I'm in the mood:
I don't think there is a strong correlation between the age at which somebody spells his first words and later academic success.
I guess if you put in the time you can teach any reasonably smart three year old a trick or two, but wouldn't they be able to learn that more quickly at the age of 6 or 7?
One of the things that helped me a lot during my studies was the ability to mentally vizualize complex topological situations. I don't think that's a skill you get from educational apps or from being able to spell your name at 8 months.
My mother in law was a preschool teacher. Parents would ask when they would learn to spell, math, etc. She would say: after they learn to wait their turn in line and stop eating the paste.
My mom's favorite story is my oldest brother could read going into kindergarden. She told the teacher, who then asked: but does he know where he lives? Nope, he didn't.
I'm not convinced that's a skill you get from anything, as opposed to an inate talent (or set of talents). I'd want to see pretty strong evidence that it could be taught to someone without the inate talent.
I'm pretty sure I'm someone with that talent, since I was never taught how to do it.
I'm sure that it's innate, because I can't visualize even simple things.
There have been a number of people who insist that they can teach me how to do that. They always start off with "Picture a..." When I tell them that I can't, I'm just being negative or uncooperative. Eventually, they get angry, throw tantrums, insult me, and stomp off like a child because I'm doing everything I can to prove them wrong, yet it never occurs to them that I simply can't do it. No, I'm always lazy, negative, and am allowing a diagnosis to define me.
True, each generation learns to function, but one should also be careful not to minimize the negative generation-wide effects of technology.
The most recent and current generations have learned to function with a huge available supply of calorie-dense, nutrient-poor foods with the consequence that record numbers of them suffer from obesity and diseases that were previously termed "adult onset" or "old age" diseases. While they have learned to function, we shouldn't deny the huge negative consequences of what technology has allowed.
There are many other examples of this (many generations "learned to function" with an overabundance of lead). We shouldn't minimize some of the negative effects of ubiquitous 2 dimensional screens just because we are used to them.
I have two children - one going into 3rd grade and the entering kindergarten. Both of them up and outside by 9am playing all day without adult supervision. We can see them from our kitchen in the field and street playing; we are monitoring them.
So was I. I was reading books to my parents and grandparents by the time I was three years old. By 8 years old, I had the reading age of an adult, and when my father eventually regained legal access to us (edit: when I was 9 years old), I was correcting his spelling, pronunciation, and grammar.
My entire family thought I was some kind of genius, but it turned out that I have a moderate-to-severe learning disability, and this was an early symptom of it.
I'm not trying to diagnose your daughter, don't even imagine that. However, I am suggesting that there may be other reasons for your daughter's apparent advancement.
Let children be children. Let them play freely. Don't push anything onto them. If they love learning reading, ok. If they don't, that's ok too and practically meaningless for their future prospect.