Don't have software but the Taylor kit does make it easy!
This is all in the booklet that comes with Taylor kit:
Test your tap water.
You know your spa's volume - so you may need to add x oz. of alkalinity increaser and y oz. of calcium increaser to get to a beginning level. PH will move up as you use alkalinity increaser.
For calcium - your done until a water change, for alkalinity or PH add 1 or 2 tablespoons of increaser to get them up.(dependent on volume)
To get alkalinity or PH down - use z oz. of PH down.
As far as dichlor - well that is hit or miss - the Taylor kit doesn't seem to work for me. But how much chlorine to get to a certain PPM is dependent on how many people are in the tub. 1 person may need 1 teaspoon but 5 people may need 2 tablespoons.
When you get the kit, read the instruction booklet - it really does explain a lot.