It depends on a few factors.
If you're bringing in a steady income, Digit can help protect your earnings and make sure that you put money away for growth.
At the same time, Digit can limit you in some ways. While Digit can be helpful for beginner investors, advanced investors may be able to outperform the app's automated service.
My take: Use Digit if you're short on time and need some motivation to start saving money or investing. If you're already well underway on your savings journey, then the app is probably not worth it.