When you create a model-driven app and deploy it to another environment such as from Dev to your Test or Production environments, your users may not see the app.
For example, in
https://home.dynamics.com (soon to be located in
https://www.office.com/apps) we have an app called UciApp1:
Our salesperson. Jeff, does not see the app – “We can’t find any apps for your role. To check for recently-added apps, select Refresh”: