StrandOrgan 11.2 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. The program lies within Audio & Video Tools, more precisely Music Production. This free software for Mac OS X was originally designed by Markus Sigg.
From the developer:
StrandOrgan lets you play the Lars Palo's sample set of the Strand pipe organ of the church in Kalvträsk, Sweden, on a MIDI keyboard attached to your iOS or macOS device. The Kalvträsk Church sample set is provided by Lars Palo under the Creative Commons Attribution-ShareAlike 2.5 license. Starting with version 10.0, the app also offers Carillon sounds. These are derived from the Lurie Carillon recordings.
You may want to check out more Mac applications, such as Speak, SH-201 Librarian or mediAvatar iPhone Ringtone Maker, which might be related to StrandOrgan.