I've tried using digit twice. However, I went off of it both times because I didn't like the random money going out of my account. Also, it is just a savings account and you don't make any interest on it.
Digit tracks spending and deposits and determines how much you can afford to save.
While this might work for people who want a way of saving where they don't have to think about it, people who what to do something to get started, or for people who don't understand their finances, I just didn't like it. Once I started budgeting I started saving more intentionally based on reality, and it was more than digit was squirreling away behind my back.
My 2 cents for what it's worth.