my daddy would be translated as "mi papi" (childish form) or "mi papito" (either childish or lewd form)
You cant say dad because dad in Spanish is a completely different word than father
Sounds like just padre and not mi padre on normal speed, leading me to put el padre.
The app accepts Dad, Mom, smart, pretty for padre, madre, inteligente and bonita. They made it super easy for how relaxed English is
Mi is the possessive pronoun, "my father" mí is usually prefaced by "a mí" making it a direct object and/or indirect object. IE "He threw the ball to me." Or in the case of gustar and encantar... Me gusta we translate as I like it. But really it's literal meaning is its pleasing to me. In such cases "a mí" is used at the beginning of the sentence to provide emphasis that whatever "it" may be is pleasing specifically to me.
Why won't it recognize my voice? I know I have a very difficult time in rolling my "r"s but it shouldn't get "mi" wrong!
In English most of our vowels are actually two sounds and in Spanish they are more pure. For example, in English our "No" is said more like "No-u" vs. Spanish where "No" is simply "No". No rounding out the o like we do in English. (It's one of the many ways Spanish speakers can tell if it's not your first language) So that's one possibility. Another possibility is that it sounded more like mí. And the other possibility is that it just didn't catch it. Happens to me all the time in the German lessons. If you have a lisp/stutter, it doesn't always catch it as well. Like if you are using voice to text on your phone. Also it just might not recognize your tonal sounds. Voice to text is picky that way. For example, if you have an iPhone, Siri doesn't always hear you right. Same with android's Google Assistant or if you download the Cortana app.
Just like in English, "Padre" is a more formal term for "Father", and "Papi" is an informal, casual term for "Dad" or "Daddy".