You can add the My Opportunities Lightning component to Salesforce mobile app by following below steps:
- Switch to Lightning Experience.
- Open any Account's record page -> click on the setup (gear) icon > and click on the Edit Page option.
- Search for the lightning component - MyOpportunities or you will see the component in the custom section on the left side menu. Drag and Drop the MyOpportunities to the Details page > Click on the Save button as shown in the image below-
- Click on Activate > Org Default > Assign as Org Default.
- For Assign Form Factor choose Desktop and Phone > Click Next > Save.
- Now you can use the My Opportunities component on your Desktop as well as on Salesforce mobile app.