You could have downloaded QRSTool 1.2 from our software library for free. The most popular version among the program users is 1.2. The software belongs to Education Tools. The common filename for the program's installer is QRSTool.exe. This free program is an intellectual property of David Towers.
From the developer:
Software for calculating several of the more popular metrics of cardiac variability that can be derived from a single electrocardiographic channel is available from the authors. QRSTool was written by David Towers. QRSTool provides a graphical user interface that will allow for the extraction of the IBI series from EKG data, whereas CMetX.
You may want to check out more software, such as QPlot, GenealogyJ or GenScn, which might be related to QRSTool.