Comparison

VTA Pay vs SENTINEL TacMap

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

VTA Pay

Features
Read full description

Download the Martha’s Vineyard Transit Authority app to easily pay for your trips on VTA Bus Transit System. The mobile app provides an easy and convenient way to securely pay for your trip, right from your phone, cash free, using a major credit card.

About

SENTINEL TacMap

This app provides advanced mission planning, navigation, and secure team communication tools. It offers features like GRG generation, line-of-sight analysis, and live position sharing with end-to-end encryption for enhanced operational coordination.

Highlights
  • Gridded Reference Graphic (GRG) generation
  • Line-of-sight and terrain masking analysis
  • Live position sharing with end-to-end encryption
  • MGRS navigation with topographic basemaps
  • Shared waypoints and overlays with live sync
  • Import/export KML/KMZ and CoT data
Features
Read full description

Sentinel is a mission planning, navigation, and team coordination platform for iPhone. Build the plan, run the mission, and keep every operator on the same picture — with end-to-end encrypted comms and live position sharing. MISSION PLANNING The math and products that normally cost you a laptop, a protractor, and time you don’t have: • Gridded Reference Graphic (GRG) generation over any structure or area • Line-of-sight and terrain masking analysis between any two points • Helicopter landing zone assessment — size, slope, and obstructions • MEDEVAC 9-Line builder with formatted, transmittable output • Range, bearing, and elevation profile between any two points NAVIGATION • MGRS • USGS topographic and imagery basemaps • Route legs with distance, bearing, and running time • Waypoint capture, edit, and bulk management ENCRYPTED TEAM COMMS Team chat secured end to end. Your traffic is unreadable to anyone outside your team, including us. Messages queue when a member drops out of coverage and deliver the moment they’re back. SATELLITE-READY Where your carrier delivers satellite data to apps (direct-to-cell on supported iPhones), SENTINEL detects the satellite link and switches to a low-bandwidth mode on its own — position reports and team messages keep moving, and map downloads wait for a full-strength connection. POSITION LOCATION INFORMATION Live PLI across the team on a shared map. See where everyone is, in real time, without a TOC, a laptop, or a tech in the truck. Set update intervals to balance fidelity against battery and bandwidth. SHARED DATA Drop it once and the whole team has it. Waypoints, hazards, rally points, objectives, and custom markers sync across every device on the mission — so the picture on your screen is the picture on theirs. • Shared waypoints and overlays with live sync • MBTiles and GeoPackage import for your own map products • Export mission data for after-action review and reporting WHO USES SENTINEL • Volunteer and county search & rescue teams • Emergency management and incident command • Law enforcement tactical and special operations units • Wildland fire and remote-area EMS • Backcountry hunters, overlanders, and expedition teams WORKS WITH YOUR ECOSYSTEM • Import and export KML/KMZ files and CoT data packages • Bundle markers, graphics, and ops data into packages and share them with your team in seconds • Runs on iPhone, iPad, and Mac with one subscription YOUR DATA STAYS YOURS • End-to-end encryption for team content — the server relays ciphertext it cannot read • No ads, no tracking, no selling data • Location sharing is opt-in, visible, and instantly revocable • Delete your account and its data in-app at any time SENTINEL PRO Your first 14 days are free, with no card needed. After that, SENTINEL Pro is $9.99 a year. One subscription unlocks the full app on all your devices. Subscriptions renew automatically until canceled; cancel any time in Settings → Apple Account → Subscriptions at least 24 hours before the period ends. Terms of Use: https://strikeapps.github.io/sentinel-legal/terms.html Privacy Policy: https://strikeapps.github.io/sentinel-legal/privacy.html A NOTE ON SAFETY SENTINEL is a coordination tool that supports trained judgment — it is not a substitute for proper training, equipment, or agency procedures. Always carry backup navigation and communication for life-safety operations. BUILT BY SOMEONE WHO USES IT Sentinel was built by a working operator tired of stitching together four apps, a laminated card, and a Sharpie to do one job. Every tool here exists because it was needed on an actual mission. PRIVACY Team communications are end-to-end encrypted. We can’t read your messages, your positions, or your mission data. No ad networks. No data brokers. No selling your location.

Screenshots

VTA Pay3 screens
SENTINEL TacMap4 screens

Verdict

The call

The clearest difference is in-app purchases: VTA Pay at none against SENTINEL TacMap's 2. VTA Pay also leads on iOS requirement (13.0 vs 26.2). SENTINEL TacMap's advantage is update cadence (every 4 days vs every 7 months). On price, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. SENTINEL TacMap sells 2 in-app purchases, starting at $5.99 per month. VTA Pay asks for nothing beyond the download.

UpkeepUpdate frequency

VTA Pay ships an update every 7 months, SENTINEL TacMap every 4 days. The most recent releases landed on September 28, 2026 and October 7, 2026 respectively.

Scorecard3 real differences · 6 level
VTA Pay versus SENTINEL TacMap: the parameters behind the verdict, then further details
ParameterVTA PaySENTINEL TacMap
PriceFreeFree
Rating—5.0 (1 ratings) — better
Number of ratings—1 — better
Update frequencyEvery 7 monthsEvery 4 days — better
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Freemium
DevicesiPhone, iPodiPhone, iPad, Mac — better
Requires iOS13.0 — better26.2
Further details — not scored
Size57 MB10 MB
Age rating4+4+
DeveloperSPX TechnologiesJEREMY MITER

In-app purchases

None

VTA Pay

No in-app purchases

2 purchases

SENTINEL TacMap

Subscriptions2
  • SENTINEL TacMap14 Days trial$5.991 Month
  • SENTINEL TacMap14 Days trial$29.991 Year

Questions

Is VTA Pay free?
VTA Pay is free to download, with no in-app purchases.
Is SENTINEL TacMap free?
SENTINEL TacMap is free to download, with in-app purchases available.
Do VTA Pay or SENTINEL TacMap have ads?
Neither VTA Pay nor SENTINEL TacMap shows ads.
Which is updated more often, VTA Pay or SENTINEL TacMap?
VTA Pay ships an update every 7 months, and SENTINEL TacMap every 4 days. Most recently, VTA Pay was updated on September 28, 2026 and SENTINEL TacMap on October 7, 2026.

Other comparisons