Once you've downloaded the mobile app, you'll enter your same email address that used when you made the purchase and then click "Forgot Password." This will then send you a link to access the App and you're in!
On the desktop portal, you'll enter the same email address that you used when you made the purchase. This will then send you a code to access the web portal. You can also select "sign in with password" at the bottom of the pop-up screen to create a password.
Also, the portal URL is changing from members.marriageignite.com to community.marriageignite.com. So update any browser bookmarks you've saved.