The print replica app
According to a release, the format is in response to "iPad users' desire for a newspaper-led experience rather than a web-based app".
The new app is available on a 30-day free trail and will then cost £4.99 a month.
Available from about 3.30pm, the app "includes the entire daily newspaper's content, as it appears in the paper, from news, sport, opinion, arts and entertainment, life & style, business and travel, and including supplements such as homes and property, alongside back issues.
"Subscribers therefore will have earlier access than most print outlets, as well as the benefit of guaranteed availability through iPad if working late or unable to find a printed copy."
Although currently a replica of the print edition, "a later release will also include interactive games and crosswords", the release states. It will also offer "enhanced commercial opportunities for advertisers".
The Standard's feeds-based app
The launch of the replica app was timed ahead of the Olympic Games and "designed to broaden the newspaper's readership; extending to fans outside of London", the release states.
Andrew Mullins, managing director, the Independent, i and London Evening Standard said in a statement: "When the London Evening Standard went free we had no choice but to restrict the availability of its distribution to central London and in the evenings only.
"Loyal readers in the suburbs and Greater London were very disappointed to no longer be able to read the Standard and repeatedly claimed they would still pay 50p if only we would make copies available.
"This new app, which brings the London Evening Standard newspaper experience brilliantly to life on a tablet platform, now allows us to be able make the Standard fully available once more to all prospective readers wherever they are.
"This development is part of our strategy to facilitate convenient availability of high quality London-based journalism across multimedia and multi-devices."