There’re different logo locations in Klinixer. All of them can be configured in
Appearance → Customise → Klinixer Customizer → Header Settings
To make your logos look crisp on Retina devices, simply upload a Retina logo to the corresponding upload fields.
Retina versions are twice as large as the original ones. For example, if your logo is
100px x 50px, the
Retina version must be
200px x 100px.