Gravitywell, the developers of Banksy London Tour, has released another exciting Banksy product for iPhone, iPod touch and iPad users. This is the follow-up app to the popular Banksy Bristol Tour and contains interactive maps to Banksy locations in London, as well as locally researched and comprehensive details of each painting. There are twenty-six locations (51 photos) included, which allow users to take a virtual tour of the surviving London pieces. Included in the app are detailed histories by experts, a guide to lost works and plenty of extras. $2.99/£1.99/download Banksy is an artist who expresses his talent with flare on the sides of buildings in cities in the U.K.…