If keeping fit seems to be a solitary, confusing exercise, here’s a solution you can wear on your sleeve. Founded by James Park and Eric Friedman, Fitbit makes wireless-enabled activity trackers that measure data such as the number of steps you walk each day, the calories you burn and the quality of your sleep. The trackers sync wirelessly to your smartphone or PC so you can track your progress over a period of time. You can also set goals and check how you have fared at the end of the day. The price of the trackers varies from $60 to $130, depending on the model. With the market for wearable technology growing bigger by the day, companies are set to make a windfall in the segment. According to Juniper Research, the market — currently pegged at $1.4 billion — is likely to touch $19 billion in the next five years, making Fitbit a company to watch out for.