Comparison

Flow Alert vs Water Snapshot

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

Head to head
About

Flow Alert

Features
Read full description

Flow Alert provides quick access to flow , stage, temperature, and turbidity data made available by the United States Geologic Survey (USGS). Download USGS gauges and add favorites to a separate list. Create nicknames for your favorite gauges. Add a widget on your home screen that shows your selected parameter for your favorite gauges. Currently, widgets update automatically approximately every 15 minutes and show a bell icon if an alert is triggered. Add alerts to notify yourself when your gauge meets your defined criteria. Multiple alerts may be set for each favorite gauge. Manage your alerts for all gauges in one screen. Select a gauge from the list to see an interactive graph of the past 7 days of available data. Data provided by: -United State Geological Survey (USGS) Disclaimer: Flow Alert provides quick access to flow , stage, temperature, and turbidity data made available by the United States Geologic Survey (USGS) via USGS Water Data APIs. All data shown in Flow Alert are downloaded from the USGS Water Data APIs. Flow Alert is not affiliated with, endorsed by, or representative of any government entity including USGS. Flow Alert does not take credit, responsibility, or ownership for any data downloaded from USGS's Water Data API. It is simply a tool that you can use to view the data made available by USGS. Data Source Link: https://api.waterdata.usgs.gov/ If you have feedback, suggestions, or feature requests, please e-mail me at flowalertapp@gmail.com...I'd appreciate it! You may also submit feedback through the in-app feedback page.

About

Water Snapshot

Access real-time river, lake, and reservoir data from trusted USGS sources. Monitor water levels, flow, temperature, and precipitation forecasts. Receive alerts for NWS flood warnings and track historical trends.

Highlights
  • View flow, elevation, and water temperature
  • Monitor rivers, lakes, and reservoirs
  • Track historical trends (24hr, 7-day, 30-day)
  • See local weather and forecast precipitation
  • Receive NWS flood alert notifications
  • Set custom water condition alerts
  • Calculate % Full for reservoirs
Features
Read full description

Water Snapshot gives you a clear picture of what’s happening at the rivers, lakes, reservoirs, and monitoring sites you care about using trusted USGS data and weather information from the National Weather Service. Track current water conditions, recent changes, historical trends, local weather, forecast precipitation, and active water-related NWS alerts in one clean, fast interface. Key Features • View Flow (CFS), Elevation, Gage Height, Water Temperature, and % Full • Monitor current conditions across rivers, lakes, and reservoirs • See 24-hour changes and observed ranges • Explore 24-hour, 7-day, and 30-day historical trends • View weather conditions near each monitoring site • See forecast precipitation totals for the next 24 hours, 3 days, and 7 days • See active NWS flood-related alerts directly alongside water conditions • Track multiple sites and metrics in one place • Set custom water-condition alerts and receive notifications • Quickly see which tracked sites have an active NWS flood alert Water and Weather in One Place Water conditions don't exist in isolation. Water Snapshot brings USGS measurements together with nearby weather and precipitation forecasts, helping you quickly understand what's happening around each site without jumping between multiple sources. When an active NWS flood-related alert applies near a tracked site, Water Snapshot can display the official alert alongside recent USGS measurements for additional context. Built for Real Use Whether you're working in water utilities, agriculture, recreation, or simply keeping an eye on local conditions, Water Snapshot puts useful site-specific information in one place without unnecessary clutter. Trusted Data Water measurements are sourced from the U.S. Geological Survey (USGS). Weather forecasts, precipitation outlooks, and water-related weather alerts are sourced from the National Weather Service (NWS). Percent Full values are calculated using reservoir-specific conservation capacity and elevation-based storage curves. Note Percent Full values may vary slightly from other sources depending on capacity definitions, interpolation, and data timing. Weather forecasts and alerts are provided for the area near each monitoring site and may not represent conditions across an entire watershed.

Screenshots

Flow Alert4 screens
Water Snapshot4 screens

Verdict

The call

The clearest difference is in-app purchases: Flow Alert at none against Water Snapshot's 1. Water Snapshot's advantage is update cadence (every 3 weeks vs every 7 months). On price, ads, device support and iOS requirement 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. Water Snapshot sells 1 one-off in-app purchase. Flow Alert asks for nothing beyond the download.

UpkeepUpdate frequency

Flow Alert ships an update every 7 months, Water Snapshot every 3 weeks. The most recent releases landed on October 26, 2026 and October 6, 2026 respectively.

Scorecard2 real differences · 7 level
Flow Alert versus Water Snapshot: the parameters behind the verdict, then further details
ParameterFlow AlertWater Snapshot
PriceFreeFree
Rating—5.0 (1 ratings) — better
Number of ratings—1 — better
Update frequencyEvery 7 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Free
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better16.6
Further details — not scored
Size34 MB35 MB
Age rating4+4+
DeveloperShaina SchwartzelAndy Jordan

In-app purchases

None

Flow Alert

No in-app purchases

1 purchases

Water Snapshot

One-time1
  • Water Snapshot Pro$4.99

Questions

Is Flow Alert free?
Flow Alert is free to download, with no in-app purchases.
Is Water Snapshot free?
Water Snapshot is free to download, with in-app purchases available.
Do Flow Alert or Water Snapshot have ads?
Neither Flow Alert nor Water Snapshot shows ads.
Which is updated more often, Flow Alert or Water Snapshot?
Flow Alert ships an update every 7 months, and Water Snapshot every 3 weeks. Most recently, Flow Alert was updated on October 26, 2026 and Water Snapshot on October 6, 2026.

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