Both Surfice and NiiVue can view GIFTI format meshes like those distributed with SPM.
With Surfice, you can drag and drop, use the File/Open menu item or you can use meshload in your Python script.
GIFTI is a common format, so it works across many tools. The exception is GIFTI files created by FreeSurfer, which can include an undocumented spatial transform that most other tools are not aware of.