--- title: "KLM Labs: iPhone apps for people who run their own work" description: "Small iPhone and iPad apps from KLM Labs: Construction Calculator, Flip Clock and Invoice Maker, plus free invoice templates and construction charts." canonical: https://klmlabs.app/ updated: 2026-11-07 --- # Small iPhone apps that each do one job For people who run their own work, and a few for everyone. ## Our apps ### Construction Calculator by KLM Labs Adds feet, inches and fractions exactly, with tools for stairs, roofs, rafters and concrete. iPhone and iPad. Free to download, with in-app purchases. Every feature, the calculator included, needs the free trial or a purchase: Yearly US$9.99 a year with a 7-day free trial for eligible new subscribers, or Lifetime US$19.99 paid once (US prices). Features and prices: https://klmlabs.app/construction-calculator/ App Store: https://apps.apple.com/us/app/fraction-feet-inch-calculator/id6816445977 [Construction charts and guides](https://klmlabs.app/construction-calculator/guides/): Seven printable construction charts: fraction to decimal, roof pitch, board feet, concrete bags, crown molding angles, stair rise and run, and square feet. ### Flip Clock by KLM Labs Turns your iPhone or iPad into a big bedside or desk clock, with alarms that ring even on Silent. iPhone and iPad. Free to download, with in-app purchases. Past the welcome page, everything (the clock, alarms and widgets) needs the free trial or a purchase: Yearly US$29.99 a year with a 7-day free trial for eligible new subscribers, or Lifetime US$39.99 paid once (US prices). Features and prices: https://klmlabs.app/flip-clock/ App Store: https://apps.apple.com/us/app/flip-clock-big-digital-alarm/id6819014371 ### Invoice Maker by KLM Labs Make an invoice or estimate on the job, even with no signal, and send it as a PDF. iPhone and iPad. Free to download, with in-app purchases. Entering your business details and first client is free; making invoices and estimates needs Invoice Maker Pro: Yearly US$39.99 a year with a 7-day free trial for eligible new subscribers, or Monthly US$6.99 a month (US prices). Features and prices: https://klmlabs.app/invoice-maker/ App Store: https://apps.apple.com/us/app/invoice-maker-estimates-app/id6815655785 [Invoicing guides](https://klmlabs.app/invoice-maker/invoicing/): Plain guides to invoice payment terms, starting with net 30: what it means, how to word it, late-fee wording and a free sample PDF. ## Coming soon Seven more apps: two in Apple's review, five in design. - [Signer](https://klmlabs.app/esign-app/): Sign and fill in a PDF, then share it. No account needed. In Apple's review. - [PDF Scanner](https://klmlabs.app/pdf-scanner/): Scan paper to PDF and search the words in every scan. No ads. In Apple's review. - [Saldo](https://klmlabs.app/budget-planner/): Log a purchase in seconds and see what's left until payday. In design. - [Mimic Game](https://klmlabs.app/mimic-party-game/): A party game for one phone: copy a sound, get a score, pass the phone. In design. - [Who Am I?](https://klmlabs.app/who-am-i-game/): Phone on your forehead: friends give clues, you tilt to guess or pass. In early design. - [Chat Story Maker](https://klmlabs.app/chat-story-maker/): Write a chat story with characters you invent, then turn it into a video. In design. - [Ambiance](https://klmlabs.app/jeux-de-soiree/): Party games on one phone, written in French first. The page is in French. In design. Every app on the way: https://klmlabs.app/coming-soon/ ## Free invoice templates and guides - [Consulting invoice template](https://klmlabs.app/invoice-maker/invoice-templates/consulting/): A free consulting invoice template PDF, filled in: hours at an hourly rate, a fixed-fee item, expenses at cost and net 30 terms, with each line explained. - [Electrician invoice template](https://klmlabs.app/invoice-maker/invoice-templates/electrician/): A free electrician invoice template PDF, filled in: labor hours, the panel and parts as separate lines, the permit fee, and the estimate it came from. - [Handyman invoice template](https://klmlabs.app/invoice-maker/invoice-templates/handyman/): A free handyman invoice template PDF, filled in: a trip charge, three small jobs on one visit each with its own hours, and materials on one line. - [Roofing invoice template](https://klmlabs.app/invoice-maker/invoice-templates/roofing/): A free roofing invoice template PDF, filled in: tear-off and shingles by the square, flashing and vents by the linear foot, decking and the permit. - [Landscaping invoice template for lawn care](https://klmlabs.app/invoice-maker/invoice-templates/landscaping-lawn-care/): A free landscaping invoice template PDF, filled in: a month of weekly mowing visits, a fall cleanup, mulch by the cubic yard and pruning hours. - [Catering invoice template](https://klmlabs.app/invoice-maker/invoice-templates/catering/): A free catering invoice template PDF, filled in: per-guest menu prices times the final headcount, staff hours, rentals, delivery and one sales tax rate. - [Photography invoice template](https://klmlabs.app/invoice-maker/invoice-templates/photography/): A free photography invoice template PDF, filled in: session fee, final images, rush delivery, prints, travel, and a plain-words usage license line. - [Net 30 invoice terms: what they mean and how to write them](https://klmlabs.app/invoice-maker/invoicing/net-30-payment-terms/): Net 30 means an invoice is due 30 days after its date. How to write net 30 payment terms, sample late-fee wording, and a free net 30 invoice PDF. ## Questions? Email support@klmlabs.app. Every app works on iPhone and iPad, with no ads. KLM Labs: support@klmlabs.app. About us: https://klmlabs.app/about/ Contact: https://klmlabs.app/contact/ Our apps on the App Store: https://apps.apple.com/us/developer/mayank-kumar-grover/id6815655787 Last updated November 7, 2026.