That app, officially known as Microsoft To-Do has been in private testing for almost a year. Starting on April 19, Microsoft To Do is available for public testing.

To-Do is a list-making app that allows users to create various task lists. As with Wunderlist, it can be used for keeping track of deadlines with reminders, due dates, and notes, and it is entirely customizable.

The preview of the new Microsoft To-Do application is available for iPhone, Android phones, Windows 10, Windows 10 Mobile, and the web starting today. (Versions for the Mac, iPad, and Android tablets are “coming soon.”) The Windows versions of the app are Universal Windows Platform apps, for those wondering.

As the company pland to retire Wunderlist, Microsoft is encouraging Wunderlist users to make the switch by offering an importer that will bring in your lists and to-dos from Wunderlist into To-Do, where those items will now be available in other Microsoft products, like Exchange and Outlook.