Use Basic a of System Font

I'm developing an app that is to be used in school districts for learning to read, so I need the letter a in the font to be the "basic" A (the a you usually write in print, not the one you see in this font with the arch over the a). I could just find a different font, but I noticed in the Apple Notes app that the font appears to be the system font, but it uses the basic a. Is there a way to do this in my own app?
I believe what you're referring to is a "one story a". Which doesn't have the swoop on top of the lower-case 'a'.
If so, the San Francisco system font has a 'one-story a', which is an OpenType alternative stylistic variant. I created a library to make using these variants in your app very easy. See here:

https://github.com/djfitz/SFFontFeatures

Doug Hill
Use Basic a of System Font
 
 
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