Marvel fans will soon be able to access 15,000 comic books via its Marvel Unlimited iOS and Android apps.

The titles span Marvel's 75-year history and include everything from classics like Captain America to more recent titles such as the reboot of Guardians of the Galaxy.

Marvel is offering the comics to customers for a one-time fee of $0.99, a reduced rate, to access the comics during March as a promotion for the company's activities at SXSW.

"We just really wanted to unlock the vault and hand over the keys in a way that allows both super-fans and people who are just curious what it's all about to check out why people love this stuff so much," said Marvel's VP of digital product Kristin Vincent. "It allows people to jump around wherever they want and get access to these classic story lines that have become part of our pop culture and also learn more about the characters they are seeing on the big screen."

Marvel Unlimited includes nearly 15,000 titles from Marvel's 75-year history. Image: Marvel Unlimited

Marvel Unlimited users can download up to 12 comics at a time to their personal library and enable offline reading for on-the-go access.

Following the month-long promotion, fans can continue their subscription to Marvel Unlimited for $9.99 a month or $69 for a year for the basic plan or pay $99 for a year of Marvel's premium plan, Marvel Unlimited Plus, which gives members additional discounts on Marvel products and a first look at Marvel news.

Marvel Unlimited is available in the App Store and Google Play Store. Fans can access Marvel's offer on Marvel's website beginning Saturday, up until March 14, by using the promo code SXSW99.

This will be Marvel's third year at SXSW. The comic-book company will be at the show to discuss the Marvel Unlimited offer and other news with fans at its panel on March 8. Fans who attend the panel will also receive a SXSW variant of the first issue of Winter Soldier: The Bitter March, a special edition only available to those attending the event.