.NET Reactor
User guide

How Locks Work

By imposing locks on your software, you can freely distribute your product for trial or evaluation, and rely upon lock expiration to compel purchase of your wares when the evaluation period expires. When software locks expire, your prospective client must purchase a valid license.
You can also set Evaluation Time, Expiration Date, and Number of Uses limits in issued licenses. When license locks expire, your customer must acquire a further license to further use your product.
By combining software and license locks, you can impose any limitations on software use you desire. Most importantly, without writing a line of code to do so, you can show off your wares to your market.