UKPMC provides WoS citation counts

"UKPMC users can now view counts and link through to Web of Science citation data for articles available via the UKPMC website. The UKPMC citations tab available on both the abstract and full text view of an article, already providing 'cited by' and 'cites the following' data, has been augmented by a WoS citation count, which links through to the full citation details on the WoS site...."