PLOS (Public Library of Science) is an open access journal service that uses the Creative Commons Attribution to license works. PLOS charges a fee to the author to publish and make the article Open Access, but the article still goes through a peer-review process.
BioMedCentral is a membership, subscription or again APC’s service to make articles open access. These journals are also peer-reviewed.
PeerJ is a peer-reviewed journal service that you can pay to publish depending on how many articles you plan to submit to their journals. Payment level link
More information on Open Access Journals There are also well known journals that have Open Access options to make your article freely available. This tool helps you select an open access journal for manuscript submission by matching your article to the topics of previously published articles in over 350 open access journals by BioMed Central, Chemistry Central, and SpringerOpen. It gives the option to select only journals with impact factors.