Applications
PropGen should be able to assist with the design and analysis of most "propeller-like" objects, which includes wind-turbines, propellers, ship screws, and tidal power turbines.
PropGen uses a variation of the Lerbs Induction Factor method, with heuristic wake dissipation corrections, to solve for induced velocities. Layered on top of the wake computations are predictor/corrector algorithms to converge to a wake solution consistent with the geometry and operating conditions. Above this are layers for multi-point optimization, and the user interface.
This is fundamentally an inviscid, lifting line method so follow up computations with higher order methods are advised before actually building something. Propeller/wind-turbines tend to fail catastrophically (it's happened to me!), so make sure you also know what you're doing on the structural side.