The scenario you have described does not have a fixed solution. It depends on what kind of application you are developing. But allowing users to login/ signin with their social accounts is the best-suited option in any case as it saves users efforts and makes the application more user-friendly. We can further classify the solution in following ways.
Scenario 1: Here you will make users mandatory to go to their email to verify their account. Here you can show a screen thanking the user for subscribing and telling him to check his email. This solution is best suited for business applications. Here you can keep an expiry time for the link
Scenario 2: Here you will ask the user to check email to verify the account. But still, you will allow the user to navigate in your app. Here you can just show a pop up telling that a link has been mailed to them for account verification. This is best suited for shopping carts and business apps where you want the user to understand your app. Here you can keep an expiry time for the link.
Scenario 3: Here you will mail the link to the user and give a small popup notifying them of the link that is emailed to them. The user is free to navigate and do any thing in app, just before doing any purchase (for shopping carts like apps) or creating lists or databases or something that needs data to be stored (for business like applications) you should remind user for verifying the account from the link. This is mostly for apps which will collect data and do nothing else.
So check your scenario and do accordingly. still using Social signin is most appropriate way.