Deck tools
Indie products their makers tagged "deck", most upvoted first.
IndieNeed is a launch site for indie makers.
The most upvoted products on IndieNeed with this tag. Tags are chosen by each maker.
Ranked products

Lumber Calc
Lumber Calc publishes free lumber calculators for board feet, log scale, stairs, deck boards, balusters, and rafters. Built for DIYers and pros, each page shows a diagram, a code check, and a shopping list.
Browse the best tools by category or every product.