What are some alternatives?
When comparing Open Tabs and Toby, you can also consider the following products
Tabs Outliner - Next Generation Session, Windows, Tabs Manager and a TooManyTabs Solution That Really Works.
Workona - A better way to work in the browser.
OneTab - Whenever you find yourself with too many tabs, click the OneTab icon to convert all of your tabs into a list. When you need to access the tabs again, you can either restore them individually or all at once.
Session Buddy - Manage Your Browser Sessions
Session Box - Using websites with multiple accounts at the same time is made easy.
Tabbie - The missing tab manager for Chrome