Money 6 tools
Mortgage Calculator
Real monthly payment plus total interest over the loan.
mortgage.sentinelletools.comCredit Card Payoff
Up to 8 cards. Avalanche vs snowball. See your debt free date.
creditpayoff.sentinelletools.comDebt Payoff Strategy
Mix cards, student loans, car, mortgage. Get the order.
debt.sentinelletools.comNet Worth Tracker
What you own minus what you owe. Stays in your browser.
networth.sentinelletools.comRental Property Cash Flow
Cap rate, cash on cash, monthly cash flow on any property.
rental.sentinelletools.com PopularFederal Salary Calculator
2026 GS base, locality, TSP, take home. Any grade, any step.
fedsalary.sentinelletools.comCompliance 3 tools
CMMC L1 Self Assessment
Score yourself on all 17 practices. Get a remediation list.
cmmc.sentinelletools.comPrivacy Policy + ToS
GDPR and CCPA aware boilerplate for any site.
privacy.sentinelletools.comGovCon Alert Service
Daily SAM.gov alerts matched to your NAICS and keywords. Free 14 day trial.
signals.sentinelletools.comWeb 6 tools
robots.txt Generator
Block GPTBot, allow ClaudeBot, set your sitemap. Copy paste.
robots.sentinelletools.comSEO Title + Meta
Five title and meta variants with character counts and SERP preview.
seotitle.sentinelletools.comQR Code Generator
Free QR codes for URLs, text, vCards, WiFi.
qr.sentinelletools.comLink in Bio Builder
Linktree style page in 30 seconds. No signup.
bio.sentinelletools.comSocial Media Bio Generator
Five LinkedIn, X, Instagram bios in different tones.
socialbio.sentinelletools.comInternet Speed Test
Download, upload, ping, jitter. Runs against a Cloudflare edge near you.
speedtest.sentinelletools.comWriting 4 tools
Readability Scorer
Paste any text, get Flesch reading ease and grade level.
readability.sentinelletools.comCover Letter Generator
Role, company, three strengths. Get a one shot cover letter.
coverletter.sentinelletools.comEmail Subject Line Tester
Score for length, spam triggers, personalization, urgency.
subject.sentinelletools.comBusiness Name Generator
Brandable names with domain availability hints.
bizname.sentinelletools.comDesign 1 tools
Dev 3 tools
Regex Tester
Live regex matching with explain mode and replace.
regex.sentinelletools.comCron Expression Builder
Pick a frequency, get the cron string, see the next 5 fires.
cron.sentinelletools.comSQL Query Builder
Visual SELECT, INSERT, UPDATE, DELETE for Postgres, MySQL, SQLite.
sql.sentinelletools.comAI 4 tools
AI Meeting Notes
Paste a transcript, get summary, decisions, action items, open questions.
meetingnotes.sentinelletools.comAI Paper Summarizer
Paste a research paper, get plain English breakdown with limitations.
papersummarizer.sentinelletools.comAI Interview Prep
Enter your target role, get 12 likely questions with strong sample answers.
interviewprep.sentinelletools.comAI Market Research
Industry plus product in, structured market analysis out. Segments, competitors, pricing.
marketresearch.sentinelletools.comWhy these exist
Every free calculator on the web seems to be a hostage situation. Five step email gates, six display ads above the answer, a 2018 GS pay table that never got updated. I got tired of it, built the ones I needed, then a few more.
Sentinelle Systems is a federal contracting firm out of Sterling Virginia (CAGE 18QJ7, UEI HVTNPB8PHKH4). I do cybersecurity work for DoD primes and subs. These tools run on the same Cloudflare stack I use for client work. Static HTML, zero third party scripts, your inputs stay in your browser unless explicitly noted.
If one of these saves you 10 minutes, the best thank you is sharing it with one person who needs it.
Federal contractor? Get the daily alerts.
Sentinelle Signals sends you new SAM.gov opportunities matching your NAICS codes every morning. 14 day free trial, $29 a month after.
Try Sentinelle SignalsNeed CMMC L2 done right?
If your contract requires CMMC L2 by 2027 and you don't have a CISO on staff, that's what we do. Monthly retainer, three tiers.
Book a discovery call