Roofing Ready Reckoner Ver 3 is an Android application developed by Gary Saunders. It is a useful tool for carpenters, builders and roofers. This app is a metric version that helps to calculate the true lengths of Hip, Valley and Common Rafters to three decimal points. It also provides the Jack Rafter diminish, Plumb Cuts, Seat Cuts, Jack Rafter Edge Cut angles in degrees for the Roof members, and newly added Purlin Edge Cut and Purlin Side Cut Angle, Hip Backing Angle, Hip Edge Angle, Plan Angle and Sheathing Angle.

The app is easy to use and can save time, money, and reduce wasted timber when pricing for roofing projects. It is also reviewed in Home Building and Renovating magazine, and the review can be read on the developer's website. However, it is important to note that this app is not a substitute for a basic understanding of roof framing, and double-checking measurements is always necessary. The developer has rigorously checked the return values but cannot accept any responsibility regarding materials, workmanship, or costs relating to the use of this Roofing Ready Reckoner.