  We calculate the cluster modular groups of affine and doubly extended
typecluster algebras in a uniform way by introducing a new family of quivers.
We use this uniformdescription to construct a natural finite quotient of the
cluster complex of each affine anddoubly extended cluster algebra. Using this
construction, we introduce the notion of affineand doubly extended generalized
associahedra, and count their facets.
