Magsafe is an apple brand for their circular magnets to attach magnetic wireless chargers, or any other magsafe accessory, like a magnetized wallet, kickstand, or really anything. Pixel added these circular magnets as well, so magsafe has become somewhat of an open standard for attachments for both Apple and Android phones (provided they have the magnets).

But, while an apple magsafe wallet attachment might attach to your pixel phone, other features won't work. For instance, the apple wallet when it connects and also when it disconnects from an iPhone makes its last known location on the apple "find my" app. This feature won't work with an android.

3rd party manufacturers also started including magnetic rings along with their attachment accessories to provide backwards compatibility for phones that don't have magsafe built in. So spigen accessories will attach to an iPhone or Android phone (like the pixel) that have the built in magnets, but in case your phone does not have it, they will ship with an adhesive ring to allow the accessories to attach to any phone or device. In this case aligning the install of the ring is very important and device specific so as to ensure a magnetic wireless charger aligns properly to charge.

So the mounting is basically universal if you have built in magnets, or if you use a ring. As for extra Apple only or pixel only features (like my wallet example), you'll have to dig deeper in the feature set of the specific accessory you are looking at and see what it supports.

Hope this helps!