You like how tags are displayed in the contact summary?
this extension does the same, for groups. You can also add the contact to a group from the summary (click on the Groups label)
Screenshot (click to enlarge)
Releases
Since CiviCRM 5.x, extension releases compatible with CiviCRM 5.0 are compatible with 5.0 and later. An extension release compatible with 5.25, for example, means that it requires CiviCRM 5.25 or later.