The 5.1.2 version of Ctrlr for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. Ctrlr for Mac lies within Audio & Video Tools, more precisely Music Production. This free Mac application was originally created by Kubiak Roman. The following version: 3.0 is the most frequently downloaded one by the program users. We recommend checking the downloaded files with any free antivirus.
From the developer:
Midi hardware editor and librarian.
You may want to check out more Mac applications, such as C.T.R.L.R, which might be related to Ctrlr.