Previously, users could only sign up for the service and link their bank accounts via a desktop browser.
The app improvements follow statements made by Coinbase CEO Brian Armstrong at the time of the company's $75m Series C fundraising, when he said development of the company's mobile product was to be a key focus this year.
This emphasis on pursuing a mobile-first strategy for an eventual expansion into emerging markets was echoed by Coinbase developer Ankur Nandwani, who told CoinDesk:
"In the developing world, most of the people are connected to Internet via their phones, and we want to make sure that they can experience the power of bitcoin."
Additional updates to the apps include support for older Android devices, instant bitcoin buying for European users and a new customer bonus program that enables new users to obtain 100 bits or around 2 cents.
Banks supported by Coinbase's instant onboarding include Bank of America, Capital One, Charles Schwab, Chase, Citibank, Fidelity Investments, US Bank, USAA and Wells Fargo.
For all other banks, US consumers are able to onboard using deposit verification.
Mobile phone user via Shutterstock