We’re at the beginning of the holiday shopping season and that means we’ll be spending a lot of time and money buying stuff online and at stores. Having the right app, however, can help save time and maybe even a few bucks, as PC Mike Wendland reports Giftster takes a social approach to holiday shopping, making it easy to shop for groups of people like co-workers, friends and family members. Users write their own lists for gift recipients, of course. But there’s also the option of getting recipients to sign up for Giftster so you can see what they want and buy it with a few simple clicks – just…