Comparison

VPD Chart vs VPD Tool

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

Head to head
About

VPD Chart

This app calculates Vapor Pressure Deficit (VPD) using air temperature, relative humidity, and canopy temperature. It offers real-time charting, sensor integration, and educational tools to understand plant growth environments. Organize data by zones and visualize dew point areas.

Highlights
  • VPD calculation
  • Interactive VPD chart
  • Sensor integration
  • Zone organization
  • Dew point visualization
  • Grow Timeline
Features
Read full description

The app calculates VPD using air temperature, relative humidity, and canopy temperature. View real-time VPD values on an interactive chart. Connect sensors for automated readings or manually input data via intuitive sliders and text inputs. Key features: • Interactive VPD chart with manual input • Default crop types • Organize charts by assigning them to different zones • Display spots that share the same VPD value • Zoom in and out of the VPD chart with a two-finger pinch and drag to pan around • VPD Target - long-press the chart to set a target VPD value • Dew point area visualization • Grow Timeline • Sync sensor historical data by importing it from sensor's app, via cloud APIs, or bluetooth • Explore sensor history by panning and zooming Supported bluetooth devices: • AC Infinity Cloudcom B2, A2, B1 • SensorPush: HT1, HT.w, HT.xw • Govee: H5051, H5072, H5074, H5075, H5100, H5101, H5102, H5103, H5104, H5105, H5174, H5177, H5179 • SwitchBot: Meter, Plus, Indoor Outdoor • Ruuvi: RuuviTag and RuuviTag Pro • Inkbird: IBS-TH1, IBS-TH1 Plus, IBS-TH2, IBS-TH2 Plus • ThermoPro: TP351, TP357, TP358, TP359 • VIVOSUN AeroLab THB1S • Shelly BLU H&T • Xiaomi Mijia 2 (LYWSD03MMC) (original and pvvx firmware) Supported devices with API connectivity: • Govee • Pulse • UbiBot • Ecowitt • Tuya • SensorPush Educational benefits: • Interactive Learning: Explore the dynamics of VPD based on changes in temperature and relative humidity by manipulating input sliders and animating the chart • Canopy - Air Temperature Link: Easily visualize and set values by linking canopy temperature to air temperature • Chart Bands Control: Toggle chart bands on/off (dew, under transpiration, prop, veg, flower, over transpiration) for a comprehensive understanding Included: 1 chart with manual input and grow timeline, device data sync & explore, default crops VPD Chart Plus subscription unlocks: • Unlimited charts • Automated VPD calculation by using sensors as the input data source • Background monitoring and Alerts (temperature, RH, VPD) • VPD history timeline, available on sensor-driven VPD charts • Custom crops Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

VPD Tool

This utility app helps growers understand Vapor Pressure Deficit (VPD) for optimal plant growth. It features an interactive heatmap and stage presets to guide environmental adjustments. Calculations are performed on-device for privacy.

Highlights
  • Interactive VPD heatmap
  • Stage-specific VPD ranges
  • Leaf and Air VPD calculation
  • Home and Lock Screen widgets
  • On-device calculations
  • CSV log export
Features
Read full description

Know your VPD in seconds. Enter temperature & humidity (or tap the interactive heatmap) to see Leaf VPD and Air VPD with scientifically labeled isolines. Choose Seedling / Veg / Flower / Late Flowering to see target VPD ranges and how best to nudge your environment to “ideal.” Why growers love it • Interactive heatmap: drag to explore temperature–humidity combos • Stage presets: recommended VPD bands by plant development stage • Leaf vs Air: leaf–air offset, dew point, absolute humidity • Beautiful widgets: small/medium/large Home & Lock Screen widgets • Private by design: on-device calculations, no account required Details • VPD = es(T) × (1 − RH/100); leaf VPD uses leaf temperature (air + ΔT) • Absolute humidity via water vapor partial pressure (ideal gas law) • Full support for °C/°F, metric/imperial • Export logs to CSV Support Questions or feedback: support@nicksberryfarm.com

Screenshots

VPD Chart4 screens
VPD Tool4 screens

Verdict

The call

The clearest difference is price: VPD Chart at Free against VPD Tool's $0.49. VPD Chart also leads on ratings volume (30 vs 1) and update cadence (every 3 weeks vs every 2 months). VPD Tool's advantage is rating (5.0 vs 4.5) and in-app purchases (none vs 2). On 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

VPD Chart is free to download; VPD Tool costs $0.49 up front. VPD Chart sells 2 in-app purchases, starting at $3.99 per month. VPD Tool asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

VPD Tool holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: VPD Chart has 30 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 74% of VPD Chart's written reviews are positive against 100% of VPD Tool's.

UpkeepUpdate frequency

VPD Chart ships an update every 3 weeks, VPD Tool every 2 months. The most recent releases landed on September 22, 2026 and September 14, 2026 respectively.

Scorecard8 real differences · 2 level
VPD Chart versus VPD Tool: the parameters behind the verdict, then further details
ParameterVPD ChartVPD Tool
PriceFree — better$0.49
Rating4.5 (30 ratings)5.0 (1 ratings) — better
Positive reviews73.7% of reviews100.0% of reviews — better
Number of ratings30 — better1
Update frequencyEvery 3 weeks — betterEvery 2 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.1 — better18.5
Further details — not scored
Size49 MB2 MB
Age rating4+4+
DeveloperINNOVO DEV S.R.L.Nicholas Hwang

Customer experience

VPD Chart

All ratings30 ratings
Positive86.7%
Neutral3.3%
Negative10.0%
Written reviews19 reviews
Positive73.7%
Neutral0.0%
Negative26.3%

VPD Tool

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

2 purchases

VPD Chart

Subscriptions2
  • VPD Chart Plus (monthly)3 Days trial$3.991 Month
  • VPD Chart Plus (annual)3 Days trial$29.991 Year
None

VPD Tool

No in-app purchases

Questions

Is VPD Chart free?
VPD Chart is free to download, with in-app purchases available.
Is VPD Tool free?
VPD Tool costs $0.49, with no in-app purchases.
Which has better reviews, VPD Chart or VPD Tool?
VPD Tool is rated higher. VPD Chart averages 4.5 out of 5 from 30 ratings, while VPD Tool averages 5.0 from 1 ratings.
Do VPD Chart or VPD Tool have ads?
Neither VPD Chart nor VPD Tool shows ads.
Which is updated more often, VPD Chart or VPD Tool?
VPD Chart ships an update every 3 weeks, and VPD Tool every 2 months. Most recently, VPD Chart was updated on September 22, 2026 and VPD Tool on September 14, 2026.

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