Firm makes device to call cab via thumb as April Fool prank
US-based taxi hailing startup Lyft has created a device as an April Fools' prank which senses when a user raises their thumb and summons a cab. The lights on the app-connected gadget blink to indicate a car is on the way and pulse when it arrives. Lyft said it has created working models, but doesn't plan to sell the gadget.