The next version of my open source feature toggling library is currently in development.
Version 3 will introduce a number of new features and retire support for some older platforms. For the currently implemented changes (not yet released at the time of writing) see GitHub release notes, and the complete list of v3 issues/features.
Some notable additions include some new toggle types to enable scenarios such as automatically enabling a feature once the assembly version number meets or exceeds a specific version and decorators to allow a toggle to default to on or off if the underlying toggle errors in some way, such as missing configuration or network error while retrieving the toggle value from a remote source such as SQL Server.
Once v3 development is complete it will be available via NuGet.