of 12 choosing "love" and "like a lot" for PBS. Since the mid-2000s, Roper Opinion Research polls commissioned by PBS have consistently placed the service as the most-trusted national institution in the United States. A 20162017 study by Nielsen Media Research found 80% of all US television households view the network's programs over the course of a year. However, PBS is not responsible for all programming carried on public television stations, a large proportion of which may come from its member stations—including WGBH-TV, WETA-TV, WNET, WTTW, WQED, WHYY-TV, Twin Cities PBS—American Public Television, and independent producers. This distinction regarding the origin of different programs on the service presents a frequent source of viewer confusion. In December 2009, PBS signed up for the Nielsen ratings audience measurement reports, and began to be included in its primetime and daily "Television Index" reports, alongside the major commercial broadcast networks. In May 2011, PBS announced that it would incorporate breaks containing underwriter spots for corporate and foundation sponsors, program promotions and identification spots within four breaks placed within episodes of Nature and NOVA, airing episodes broken up into segments of up to 15 minutes, rather than airing them as straight 50- to 55-minute episodes. The strategy began that fall, with the intent to expand the in-program breaks to the remainder of the schedule if successful. In 2011, PBS released apps for iOS and Android to allow viewing of full-length videos on mobile devices. Vern Seward of The Mac Observer calls the PBS iPad App, "...cool on so many levels." An update in 2015 added Chromecast support. "PBS UK" was launched as a paid subscription channel in the United Kingdom on 1 November 2011, featuring American documentary programming sourced from PBS. Better identifying its subject matter, this channel was renamed "PBS America" on 4 July 2012. The channel has subsequently become available in other parts of Europe and Australia. On February 28, 2012, PBS partnered with AOL to launch Makers: Women Who Make America, a digital documentary series focusing on high-achieving women in male-dominated industries such as war, comedy, space, business, Hollywood and politics. PBS initially struggled to compete with online media such as YouTube for market share. In a 2012 speech to 850 top executives from PBS stations, Senior Vice President of Digital Jason Seiken warned that PBS was in danger of being disrupted by YouTube studios such as Maker Studios. In the speech,