Comparison

PhosphorHertz vs SimpleFT8

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

Head to head
About

PhosphorHertz

Features
Read full description

PhosphorHz is a real-time HF radio propagation monitor for amateur radio operators. It pulls live space weather data from NOAA's Space Weather Prediction Center and translates it into band-by-band conditions you can act on โ€” right now, from your location. No guesswork. No stale forecasts. Just the numbers, rendered in a retro CRT phosphor display that would look at home in a Cold War listening post. BAND CONDITIONS See at a glance which HF bands are open, marginal, closed, or blacked out. Conditions are calculated from real-time solar flux, geomagnetic activity, and X-ray flux data โ€” not generic regional forecasts. Each band shows your local status plus path-specific conditions to every DX target you configure. MUF CALCULATION The Maximum Usable Frequency for a 3000km reference path from your QTH, derived from Solar Flux Index, solar zenith angle, and depressed by geomagnetic activity. Individual MUFs are calculated for each great-circle path to your DX targets, because the ionosphere doesn't care about averages. SOLAR INDICES All the numbers that matter, updated in real time: Solar Flux Index (SFI) with 30-day trend chart Planetary Kp Index with 24-hour bar chart Estimated Sunspot Number (SSN) GOES X-ray flux class and latest flare detection Solar wind IMF Bz component NOAA R/S/G scales (Radio Blackout, Solar Radiation, Geomagnetic Storm) Running A-index and solar wind Bt Each index includes a plain-language assessment: is the F2 layer well ionised? Is the geomagnetic field quiet or disturbed? Is the solar wind coupling or shielded? 3D GREYLINE GLOBE A SceneKit globe shows the solar terminator โ€” the boundary between day and night โ€” in real time. The greyline (twilight zone along the terminator) is where lower-band DX propagation is enhanced, and it's rendered as an amber band you can see at a glance. The globe displays coastlines, your QTH position, DX target locations, and great-circle paths coloured by band condition. Drag to rotate. Double-tap to recentre on your station. Hit play to watch the Earth spin. SPACE WEATHER ALERTS NOAA SWPC alerts and warnings filtered for HF relevance. Flare events, geomagnetic storms, radio blackouts โ€” the alerts that actually affect your ability to make contacts, with full detail on tap. DX TARGETS Configure up to five target regions. PhosphorHz calculates path-specific propagation for each one, using great-circle geometry and the MUF at the midpoint of each path. What's open to Japan might be closed to South America โ€” and now you can see both at once. FEATURES Real-time data from NOAA SWPC (public domain, no API key required) Band conditions for 160m through 6m Path-specific propagation to multiple DX targets 3D interactive greyline globe with terminator visualisation Sunrise/sunset times and countdown to next solar event Day/night/greyline status at your QTH Kp index 24-hour bar chart SFI 30-day trend line Full space weather alert log with 30-day history Maidenhead grid locator display Automatic location detection or manual grid entry Green phosphor and amber phosphor CRT themes CRT scanline overlay effect Designed for iPhone, portrait orientation No ads. No tracking. No subscription. Part of the Phosphor suite: PhosphorWX (aviation weather), PhosphorRad (radiation monitoring), PhosphorSol (space weather), and PhosphorOrbit (satellite tracking). 73 de PhosphorHz.

About

SimpleFT8

This app enables ham radio operators to send and receive digital signals using FT8 and FT4 modes. It facilitates long-distance communication even in challenging conditions, allowing for local logging and optional global propagation mapping.

Highlights
  • Live decode table
  • Slot-aligned transmitter with QSO composer
  • Built-in waterfall display
  • Local QSO logbook with ADIF export
  • Map of decoded stations
  • Optional PSK Reporter integration
Features
Read full description

SimpleFT8 is a native macOS and iOS app for FT8 and FT4, the weak-signal digital modes used by amateur radio operators worldwide. WHAT IS FT8? FT8 is a structured digital mode for ham radio. Stations alternate transmitting and receiving in synchronized 15-second slots, exchanging compact messages over a narrow audio bandwidth. The mode decodes successfully at signal levels well below the noise floor โ€” operators routinely make contacts on a watt or two of power with stations on the other side of the planet. SimpleFT8 puts a real digital station in your pocket. Decode signals using your device's microphone or a USB audio interface and send replies in the next slot. The manual station and local logbook work without an account. WHAT YOU GET โ€ข Live decode table per 15-second FT8 or 7.5-second FT4 slot โ€ข Slot-aligned transmitter with a structured QSO composer (CQ / reply / report / RR73 / 73) โ€ข Tap any decode to start a QSO โ€” the state machine handles the rest of the handshake โ€ข Built-in waterfall display with tap-to-set TX frequency โ€ข Local QSO logbook with search, editing, ADIF import/export, and complete native backup/restore โ€ข Map of stations you've decoded with their Maidenhead grids SIMPLEFT8 FREE Free includes unlimited FT8/FT4 receive, waterfall and decode history; microphone and USB audio; manual CQ, reply and complete QSO exchanges; all TX safety controls; local logging and full portable ADIF import/export; and the basic community map. SIMPLEFT8 PRO โ€” ONE-TIME LIFETIME UNLOCK Pro adds automatic replies, custom-message looping, advanced export scopes, direct QRZ Logbook transfer, and private iCloud log sync. On macOS, Pro also adds Icom CI-V CAT/PTT and VFO control over a serial connection, System Audio capture, and autonomous band hopping. CAT/PTT rig control and band hopping are not available on iPhone or iPad. No subscription. Customers who bought SimpleFT8 before it became Free receive Pro automatically. PSK REPORTER + PRESENCE (OPT-IN) If you turn it on in Settings: โ€ข Decode reports forwarded to PSK Reporter so you contribute to the global propagation map (rate-limited server-side) โ€ข See who heard you in the last 15 minutes, plotted on the map โ€ข See other SimpleFT8 operators currently online, on the same map Both toggles are off by default. QRZ transfer and private iCloud log sync are also separately configured and off by default. WHAT MAKES IT DIFFERENT โ€ข Native Swift/SwiftUI โ€” no Electron, no Qt port. Looks and feels like a Mac/iOS app should. โ€ข Pro System Audio capture on macOS via ScreenCaptureKit โ€” decode straight from SDR software, WebSDR, or any audio your machine is playing, without a virtual cable. โ€ข Random caller selection rather than first-come โ€” every station in a pile-up has an equal shot at being picked. โ€ข Opinionated QSO state machine handles slot parity, role alternation, and protocol step transitions so you don't have to fight the radio. PRIVACY The app is foreground-only on iOS โ€” the mic stops when the app goes to background. macOS keeps audio I/O alive (long FT8 sessions are the norm). Optional community and logbook integrations are clearly opt-in. No analytics, no tracking, no ads, and no subscription. Built by a ham operator for ham operators. 73 de PD3BAL.

Screenshots

PhosphorHertz4 screens
SimpleFT83 screens

Verdict

The call

The clearest difference is price: SimpleFT8 at Free against PhosphorHertz's $0.99. SimpleFT8 also leads on update cadence (every 2 weeks vs every 4 months) and iOS requirement (17.0 vs 26.2). PhosphorHertz's advantage is in-app purchases (none vs 1). On ads and device support there is nothing between them.

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

CostPrice ยท In-app purchases ยท Ads ยท Monetization

SimpleFT8 is free to download; PhosphorHertz costs $0.99 up front. SimpleFT8 sells 1 one-off in-app purchase. PhosphorHertz asks for nothing beyond the download.

UpkeepUpdate frequency

PhosphorHertz ships an update every 4 months, SimpleFT8 every 2 weeks. The most recent releases landed on October 31, 2026 and November 9, 2026 respectively.

Scorecard4 real differences ยท 4 level
PhosphorHertz versus SimpleFT8: the parameters behind the verdict, then further details
ParameterPhosphorHertzSimpleFT8
Price$0.99Free โ€” better
Positive reviewsโ€”100.0% of reviews
Update frequencyEvery 4 monthsEvery 2 weeks โ€” better
AdsNoNo
In-app purchasesNo โ€” betterYes
Monetizationโ€”Free
DevicesiPhone, iPadiPhone, iPad, Mac โ€” better
Requires iOS26.217.0 โ€” better
Further details โ€” not scored
Size5 MB6 MB
Age rating4+4+
DeveloperStuart WoolleyJeroen Rombouts

In-app purchases

None

PhosphorHertz

No in-app purchases

1 purchases

SimpleFT8

One-time1
  • SimpleFT8 Pro$3.99

Questions

Is PhosphorHertz free?
PhosphorHertz costs $0.99, with no in-app purchases.
Is SimpleFT8 free?
SimpleFT8 is free to download, with in-app purchases available.
Do PhosphorHertz or SimpleFT8 have ads?
Neither PhosphorHertz nor SimpleFT8 shows ads.
Which is updated more often, PhosphorHertz or SimpleFT8?
PhosphorHertz ships an update every 4 months, and SimpleFT8 every 2 weeks. Most recently, PhosphorHertz was updated on October 31, 2026 and SimpleFT8 on November 9, 2026.

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