Strava uses the freemium model; that is, it offers some features for free, and others you have to pay for. I would think this would apply for almost every cycling app. In fact, I wouldn't use one that didn't have a revenue stream. It's going to run out of money eventually, or the developer will drop support when he needs to get paid.
Since Strava has found that people will pay per month the sort of amount that most other apps charge as a once only fee for the pro/ad free version, all the other bicycling apps do much the same. Endomondo and RWGPS both have a monthly subscription service.