Acorns
Putting money back for the future is almost always a good idea — but for many people, it's damned hard to do. Acorns makes it easy, by rounding up the odd totals when you purchase stuff with your bank card, and using the change to make investments. Your portfolio is optimized based on your income and investment goals, and the rest is taken care of for you, with low fees, no commissions, and no minimum balance. Importantly, it's also fun to check and see how much you've put in and how much you're expected to earn, making it far more exciting than opening the Stocks app.
