If you'd like early access to updates and to test new features, then we'd love to have you as a Microsoft To-Do Insider on our Windows 10 and Android apps. It's easy to easy to get started:
For Windows, you just need to become a Windows Insider. You can join the program by visiting Insider.Windows.com
For Android, you can join our public Android Insiders group here.
For iOS, you'll first need to install TestFlight on your iOS device. You can find it in the App Store or just click here. Once TestFlight is installed, just visit https://testflight.apple.com/join/JSq3UkAz from your device. You'll then be able to download and install our Insider's build via TestFlight.