Is there a single page where I can view Lightning Home Assignments? I am looking for something like how you can see page layout assignment by profile and record type for an object, but I want it for App and Profile. Does this information exist on one page somewhere? Thanks!
There is no standard apex query or class for this and there is no UI unless you go to Lightning App builder and look at each Lightning page.
However if you are really interested to know, this is present in the metadata named "Profile Override".
Profile Override is a part of custom Application metadata.
You can build a viewer in apex using tooling api. Here is a starter code to get you started on this.
Http h = new Http(); HttpRequest req = new HttpRequest(); req.setEndpoint(Url.getOrgDomainUrl().toExternalForm() + '/services/data/v48.0/tooling/query/? q=Select+Id,Metadata+FROM+CustomApplication'); req.setMethod('GET'); req.setHeader('Authorization', 'Bearer ' + UserInfo.getSessionId()); HttpResponse res = h.send(req); System.debug(res.getBody());
The response has profileOverrides for every application that has record type and profile assignments for every lightning app.