Mountain View-based Google has acquired Gizmo5, a developer of a voice-over-IP software product and related VoIP service, the firm said Thursday afternoon. Financial details of the buy were not disclosed. Google said it will add Gizmo5's engineers to its Google Voice team. As part of the buy, Google said it is suspending new signups to Gizmo5, and that existing users will no longer be able to signup for a call-in number to the VoIP service. No details on the plans for Gizmo5's products was otherwise announced.