No. Only the owner of the app (you) can see the Edit Icon above your app.
You can see the Edit Icon because you are logged in to your POWR.io account, and the app recognizes you as the owner.
To test this, log out of your account at POWR.io, then refresh the page and the Edit Icon should disappear.
If your Edit Icon appears even after logging out of your POWR account, please make sure that your App is saved. Unsaved Apps show the Edit Icon to all users viewing the page. Click on Edit, go through the setup steps, and click the green Save button in the last editing tab to properly save your App.
View more information about the edit icon in this video: