Dogs enjoy roaming around. They also tend to be rather precious to their owners, which is why we're hesitant to let them off the leash. With the WhistleGPS Dog Monitor, you won't have to worry (as much). This small weatherproof monitor uses GPS and Sub-GHz cellular technology to keep tabs on your pooch, periodically syncing its location with Whistle's servers or letting you locate them on demand. Using the app, you can see where they are and where they've been, all for just $5 a month — which is a pretty small price to pay for added piece of mind.