This is a program that allows you to visualize your gRNA sequence as well as homology arm primers in the context of the gene itself. In addition this program can give you your primers with Gibson Assembly sequences as well as your gRNA with the overhangs necessary for insertion into the spCas9/gRNA backbone.
Protocols for primer design were from https://media.addgene.org/cms/filer_public/48/9c/489c5d30-2f03-4ed0-a09c-d69a0c41da2f/addgene_pfetch_donor_protocol.pdf. Protocols for gRNA were from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3969860/. The overhang sequences for the gRNA can be found in Figure 4C of that protocol.
Primer sequences were obtained with the NCBI Primer-BLAST tool. gRNA sequences were obtained using Atum Bio's gRNA design tool and confirmed using Zhang Lab's gRNA design tool.