Once your JCurve mobile app is installed, you will be able to see your JCurve mobile app under the 'Sales Channel Section' on the left menu of your Shopify dashboard (not App Section)
You can also access your JCurve mobile app by clicking on the plus (+) sign next to the sales channels section.
Simply click on the (+) icon and the page below will open up. Click on 'Manage sales channels' at the bottom of the page as shown below.
Let us know if you have any further questions. :)