The Ring Doorbell installs easily in minutes, with no professional help or additional tools required. A built-in rechargeable battery lets you install the doorbell anywhere, or connect it to existing doorbell wiring. Motion-triggered alerts sent via the free Ring™ app (iOS® and Android™) notify you of arriving guests and deliveries. Cloud Recording ensures you'll never miss any activity at your home. With Ring, you're always home. Ring Doorbell's operate without a subscription, providing the same real-time notifications and live streaming video of events without saving a video of the event. However if you would like to automatically save recordings of both doorbell triggers and motion triggers Rings cloud video recording plans are optional and cost just USD$3/month or USD$30 annually and allow you to store 6 months of video recordings. So even if you can't get to your phone you'll know who's been calling.