Kudos!
I am always glad to see more accessibility in software.
For regular (non-disabled user base) apps, it’s quite possible to make apps accessible, but it’s something that should be planned from the beginning (same with localization).
I do it with almost all my apps. Pretty simple, if you integrate it from the start.
One tool that I always suggest, is Sim Daltonism[0]. It’s a great way to ensure that we don’t rely on color alone, as a UI feedback axis.