Artificial spin-ice (ASI) lattices are artificially created structures made of arrays of strongly interacting nanomagnets that were originally envisioned to mimic the behavior of crystalline spin ice. However, the term "artificial spin ice" broadly refers to a larger class of magnetic metamaterials where magnetic domains can be mapped onto a spin-lattice model. Recently, ASI has been implemented in functional magnonics - a research field that utilizes magnons, the quantized excitations of spin waves. Magnons show complex properties, which can serve as model systems for a variety of physical phenomena and a platform for low-power information processing. From this end, ASI is well suited for reprogrammable magnonic crystals where an interplay between geometry, material properties and reconfigurability can be used to modify the spin-wave spectrum with on-demand feature toggling.