A few weeks after extending its “all access” subscription plans to Time magazine, Time Inc. (NYSE: TWX) is working on creating tablet editions for its entire roster of 21 titles by the end of 2011. In addition to Time, the publisher currently markets tablet versions of People, Sports Illustrated and Fortune. Of the 17 mags currently without a tablet edition, InStyle, Real Simple and Entertainment Weekly are likely to get the digital replica treatment first.

Separately, Time also said it has struck an agreement with Barnes & Noble (NYSE: BKS) to sell digital subscriptions and single-copy issues of its four existing tablet editions on the NOOK Color starting later this month, with the rest of the portfolio to follow by year-end.

The B&N deal adds the Nook Color to a growing list of platforms where Time Inc. distributes its digital titles, including Apple’s iPad, Google’s Android Marketplace, HP (NYSE: HPQ) TouchPad and Next Issue Media’s store.