Opera allows you to connect your instant messaging accounts to the browser as well. That lets you instantly access your conversations from the sidebar. It's compatible with a couple of popular services including WhatsApp, Facebook Messenger, Telegram, and VK.
To link your accounts, you will have to first ensure your preferred platform is available on the sidebar. If it's not, head into the Settings and under Manage Sidebar, switch it on. Then, all you need to do is tap its icon and Opera will load the login screen.