To retrieve all App definitions including ones that were not deployed at runtime:
GET api/enterprise/models?filter=myApps&modelType=3&sort=modifiedDesc
The request parameters
- 
filter : Possible values: myApps, sharedWithMe, sharedWithOthers, favorite.
 - 
modelType : Must be 3 for App definition models.
 - 
sort : modifiedDesc, modifiedAsc, nameAsc, nameDesc (default modifiedDesc).