We have a user sign up form in our product. In web version we have a email verification process. We will send a verification mail with an activation link after sign up.

Now we have a mobile app for the same product.I feel like following the same process is not good on a mobile because it makes the sign up process longer and user needs to use his mail client and browser to complete sign up process.

A "loooong" process in mobile is really bad, How can we solve this issue.