SWIFTSCALES Perfect Pitch Pipe is a free mobile app developed by VELDEN, available on the Android platform. The app is designed for performing singers, acapella groups, vocal coaches, barbershop quartets, and armchair harmonizers. It accurately recreates a real-world pitch pipe and adds functionality and customizability never before seen in a mobile app. The audio is professionally recorded by the London Philharmonia.

The app features over 4 octaves of notes and allows users to customize the note range. It also has 9 one-tap chorded modes for harmonizing and supports every mobile device size/shape. The app is the first fully adaptive pitch pipe app, and users can save their own custom presets. In addition, there is a video tutorial detailing app usage. The vast majority of the features in this app are available free of charge, ad-supported. Users may upgrade via a one-time in-app purchase to enable extended app features and remove advertisements.

Overall, SWIFTSCALES Perfect Pitch Pipe is a useful and user-friendly app for singers and harmonizers. It is highly recommended for those who are looking for a reliable and customizable pitch pipe app.