The 2.5 version of Horizon 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. The program lies within Business Tools, more precisely Finances.
The actual developer of this software for Mac is Lucerne Systems. This application works fine with Mac OS X 10.6 or later. We recommend checking the downloaded files with any free antivirus. The unique ID for this app's bundle is com.lucernesys.horizon. The most popular versions among the program users are 2.1 and 1.3.
From the developer:
Horizon is a unique financial management application that uses a one-of-a-kind calendar interface. To record income and payments, you simply click on a date and enter an amount. Horizon gives you the ability to categorize your incomes and expenditures, repeat re-occuring events, and quickly summarize everything between any two points in time.
You can hide and show different categories to focus on different aspects of your finances.
You may want to check out more software for Mac, such as VMware Horizon View Client, Pirates of New Horizons: Planet Buster or Mystery of the Crystal Portal - Beyond the Horizon, which might be related to Horizon.