I test each service's prominent features, but it's up to you to decide whether or not you need dial-in numbers, VoIP, or both options for your audio, and whether or not you need video calls in addition to screen sharing. Some services offer both teleconferencing with dial-in numbers (local or toll-free) and VoIP calling, while some offer just one or the other. A few offer international dial-in numbers. Adobe Connect doesn't offer teleconferencing at all but can be integrated with a number of other services. Most offer video calls via webcam, although a few don't.
Any smart doorbell worth its salt is equipped with a video camera that sends an alert to your phone along with a live video stream when the doorbell button is pressed. Video is accessed via a mobile app that is also used to install the device, configure wireless settings, and set up alerts. You'll pay more for doorbells that offer features like 1080p video, motion detection, two-way audio that lets you speak with whoever is out there, and on-demand video streaming. To avoid false alerts from passing cars, high winds, and any critters you may have roaming around your property, look for a doorbell cam that offers customizable motion zones.
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