Smartwatch maker Pebble, which had the highest-funded campaign in the history of crowdfunding website Kickstarter, has shut down. The startup's software assets will reportedly be acquired by fitness band maker Fitbit for less than $40 million. Pebble had raised over $20 million on Kickstarter from more than 78,000 backers and claims to have shipped over 2 million smartwatches globally.