Bank of America’s Customized Cash Reward card gives you 3% minimum on anything you buy online or through an app. I buy as much as I can online and though apps using it.
https://www.bankofamerica.com/credit-cards/products/cash-back-credit-card/
You can also get a bonus above the 3% if you have even a small relationship with BoA. If you have an IRA with just $20,000 in it then you can get a 25% bonus, if you have $50,000 in your IRA then you get a 50% bonus, and if you have $100,000 in your IRA then you can get a 75% bonus.
So using a 50% bonus, the card gives you 3% * 1.50 = 4.5% cash back for all online and app purchases. You can buy gas, groceries, crap from Amazon, even fast food using apps or websites and get that additional bonus. If you travel and book your reservations online you can get the bonus for those purchases also.
https://promotions.bankofamerica.com/preferredrewards/en#benefits
h/t TO_GOF