SnapGene can open some Geneious Prime .geneious files, see this link.
Provided a Geneious Prime file (.geneious) contains only DNA sequences then it can be imported into SnapGene. Any annotation (feature) information associated with the nucleotide sequence will also be imported and displayed in SnapGene.
SnapGene cannot currently import Geneious Prime files that contain one or more alignments, assemblies, sequence list files or other Geneious data types.