Digit is a personal finance tool that aims to help Millennials struggling with student loans, rent and other bills to start putting money into savings. It works  by linking to your checking account, analyzing your income and spending patterns and automatically withdrawing small amounts to put into savings.

That hands-off functionality is something that Millennials crave in their tech-focused and automated-leaning preferences across all their platforms. 

Tiffany Welka, a Millennial and a financial advisor in Livonia, Mich., was impressed by Digit's no-frills approach when she tried it out recently. “It is a tool that I feel Millennials would really enjoy if they’re trying to save, especially if they’re poor budgeters,” Welka said. “The thing I really liked about it is that you don’t have to tell it how much you want to save."

Compared to other savings tools, Digit requires little intervention by the user. “We’re the only savings service that is actually truly fully automated," said Ethan Bloch, CEO of San Francisco-based Digit. To be precise, Digit examines the user's checking account payment and deposit activity and determines how much can safely be transferred to savings without risking an overdraft.

The transferred amounts are typically small, $5 to $50. Bloch says their average user saves $100 a month through transfers occurring approximately every three days. Users get text messages keeping them abreast of activities and can pause withdrawals if account balances get too low, The service offers to pay overdraft charges should it miscalculate. Bloch says the company has paid some overdraft charges.

There are a number of apps and services to help people start saving with varying degrees of automation. Most banks, for instance, permit customers to set up regular repeating transfers from checking to savings. Users of Betterment, the robo-advisor for 401(k) accounts, can direct the service to monitor checking account balances and sweep any funds above a pre-set amount into an investment account. Acorns, another Millennial-targeted app, rounds up to the nearest dollar purchases made with a card and deposits the change into a savings account.

Digit doesn't charge for its service as some other savings apps do. Instead the company makes money from interest on funds users deposit. The users don't get any interest. Because Digit isn't a bank, Bloch said; it isn't allowed to pay interest. However, there is a bonus program that pays users 5 cents for keeping $100 in a Digit account for three months.

The text message interface is another differences. Instead of having users communicate through an app or web pages, Digit uses text messages to let users know what is going on and to receive commands from users. For instance, if a user wants to make an extra deposit, the command is sent by text message. Withdrawals from the Digit account are also accomplished via texting.

Welka appreciated the simplicity of the text interface. The brief messages make it easy to figure out what's going on and communicate with the service, she said. "It’s a little less overwhelming than banking apps or banking websites,” she said.

Digit is not a bank, so funds are deposited in other institutions, including Wells Fargo Bank, BofI Federal Bank and Opus Bank. The accounts are FDIC-insured like any other savings account.

Digit targets Millennials who are having trouble getting started saving. It's not for people who already have thousands of dollars saved up. Bloch said the average user is in his late 20s and earns between $15,000 and $80,000.

Bloch said tens of thousands of Digit users have saved about $50 million so far. Future developments at the company will likely include helping users save and invest their growing stashes, he said.

Welka said she'd consider recommending Digit to her Millennial clients who are having trouble getting started saving. “I hear sometimes that people say they can’t afford to save," she said. "This helps you see that you actually can.”