Everything you measure, calculate and clock — in one offline app.
CHERP Solo is a field toolkit for one tradesperson. No crew, no account, no signal needed. Open it in a basement mechanical room with no bars and every part of it still works.
FEET AND INCHES CALCULATOR
Add, subtract, multiply and divide in feet, inches and fractions down to 1/16" — the way a tape measure actually reads. Quick-tap fraction buttons, a decimal-to-fraction converter for laser readings, and a running tape that survives closing the app. Tap any past result to drop it straight into your next calculation.
Shortcuts for the math you do on your knees: 45° and 22.5° offsets, 1/4" per foot slope, circumference, double and half.
CALCULATORS AND REFERENCE FOR YOUR TRADE
Pick your trade and the app tailors itself — pipe trades, electrical, HVAC, fire sprinkler, carpentry, concrete, insulation, civil and general construction. Trade calculators, conversion tables and quick-reference charts, all stored on the phone and ready offline. Switch trades whenever the work changes.
TIME CLOCK AND WORK HOURS
Clock in and out on the job. CHERP Solo tracks the day, splits overtime past your daily and weekly thresholds, and totals the week for you. Export a timecard CSV whenever hours have to go to the office.
PAY ESTIMATE
See what the week is worth before payday. Enter your hourly rate once and it is remembered. Set your normal week, filing status and dependents, and the estimate accounts for federal tax brackets, the standard deduction, W-4 dependent credits, FICA and your state rate. An estimate, not a pay stub — but a close one.
JOB LOG AND CALENDAR
A month view of your work. Tap a day to see everything logged on it: hours, tasks, photos, safety records. Export any day as a PDF or JSON to send on.
TASKS, PARTS AND SAFETY
Keep a punch list, track the parts you still need, and complete a JSA before the work starts. Snap photos straight into the job log.
ONE-TIME PURCHASE
Buy it once and it is yours. No subscription, no ads, no upsells, no trial that expires mid-shift. Every calculator, every table and every feature is included the day you install it.
YOUR DATA IS YOURS
• No account, no login, no email address.
• No ads, no tracking, no analytics.
• No servers — nothing leaves the phone unless you send it.
• Full backup and restore to a single file, so a new phone is not a fresh start.
Built for the trades: pipefitters, sprinkler fitters, electricians, HVAC techs, carpenters, concrete and insulation crews, and anyone who works a tape measure and a time card.
Calculators and reference tables are field rules of thumb, not stamped engineering. Always verify before you rely on them.
CHERP Solo is the single-user tier of the CHERP family, from Debe Corporation.
Feet-inch calc, time clock, pay estimate. Offline. No ads, no subscription.