Rattlegram vs icMercury
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Rattlegram
This app utilizes advanced COFDM technology for audio-based SMS transmission. It supports various modes with specific encoding and modulation techniques, requiring minimal bandwidth for efficient data transfer.
- COFDM technology
- Audio-based SMS
- 160 ms OFDM symbols
- Differential PSK modulation
- Forward error correction
- Low bandwidth requirement
Read full descriptionHide full description
COFDMTV is based on COFDM (coded orthogonal frequency-division multiplexing) technology: - 160 ms long OFDM symbols - 6.25 Hz per sub-carrier - 1/8 guard interval - differentially encoded PSK (phase-shift keying) modulation - systematic polar codes for forward error correction Currently Modes 14, 15 and 16 are supported: Using either SPC(2048, 1392), SPC(2048, 1056) or SPC(2048, 712) with CRC32C aided SCL decoding and differential QPSK modulation for the payload. Only a bandwidth of 1600 Hz is needed and the transmission of either 85, 128 or 170 bytes take about one second with the leading noise and fancy header disabled.
icMercury
Read full descriptionHide full description
icMercury is your gateway to space tracking, celestial exploration, and cosmic storytelling. Key Features: Satellite Tracking – Follow satellite movements and orbital paths with your virtual interface. Cosmic Alerts & Events – Stay updated on upcoming celestial events and much more beyond. Space Missions & Insights – Access astronomical data, mission updates, and space insights. Personalized Space Feed – Discover trending space news and scientific discoveries. Share Your Stellar Story – Post, discuss, and engage with a global space-loving community. Why Choose icMercury? Advanced astronomical data sources. Designed for smooth navigation and an immersive experience. Connect with fellow space enthusiasts and share your observations. Join icMercury and embark on a journey beyond Earth! Download now and explore the infinite possibilities of space!Whether you're an astronomy enthusiast, space researcher, or stargazer, icMercury brings the cosmos closer to you with latest technology and an intuitive interface
Screenshots
Verdict
The clearest difference is update cadence: icMercury at every 5 days against Rattlegram's every 9 months. icMercury also leads on iOS requirement (15.1 vs 17.6). On price, ads, in-app purchases 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Rattlegram ships an update every 9 months, icMercury every 5 days. The most recent releases landed on September 8, 2026 and September 19, 2026 respectively.
| Parameter | Rattlegram | icMercury |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (23 ratings) — better | — |
| Positive reviews | 90.0% of reviews | — |
| Number of ratings | 23 — better | — |
| Update frequency | Every 9 months | Every 5 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.6 | 15.1 — better |
| Further details — not scored | ||
| Size | 1 MB | 67 MB |
| Age rating | 4+ | 12+ |
| Developer | aicodix GmbH | Interstellar Communication Holdings, Inc. |
In-app purchases
Rattlegram
No in-app purchases
icMercury
No in-app purchases
