You can log in on any device (desktop, laptop, tablet, phone, etc.) by going to the Karani homepage. To log in to your Karani account, click "Log in" on the top menu bar.
It'll pop open the window below.
You can either log in with your Google account, or with a Karani account:
Type in your email address.
Type in your password.
Click "Sign in" and you'll be logged into Karani.