Blue Box vs DataLeft
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Blue Box
Encode and decode DTMF signals using your device's microphone or keypad. Play back tone sequences with adjustable settings, and save them for easy recall. Explore various tone systems, including trunk control and coin signals, for educational and utility purposes.
- Encode/decode DTMF signals
- Adjustable tone, delay, and volume
- US, UK, and European tone systems
- Multi-frequency and trunk control tones
- Coin tone sequences (Red Box mode)
- Custom tone creation
- Save and organize sequences
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Blue Box is utility for encoding and decoding DTMF (Dual-Tone Multi-Frequency) or Touch Tone signals. Generate tones by using the phone style keypad or decipher tones using the device’s microphone. Tone combinations can be played back with adjustable tone, delay and pause lengths and volume. Choose from US, UK and Europe based systems. Enable Multi-frequency tones, which were a precursor to DTMF. Additional trunk control signals will be available including KP, ST1, ST2, ST3, KP/ST2. Additional tones include the Dial Tone, Ring Back Tone, Busy Signal and 2600Hz. A comma can be used as a pause character to provide extra time between tones during playback. Save and organize any number of sequences for easy recall using the Favorites feature. Choose numbers from your contacts to display and play back tones. Share an encoded or decoded number with the Phone, FaceTime or Messages app. Use Red Box mode to play coin tone sequences, including 5¢, 10¢ and 25¢ for the US system and 10p and 50p for European systems. Create a custom tone with control over individual frequencies and volumes. The custom tone can consist of any number of on and off pulses and can optionally be continuous. Record interactions with the encoder and play them back with the same timing. The recording feature works with all tones, including the dial tone, busy signal, ring back tone, 2600Hz and coins and trunk control tones. A help manual is including, with step-by-step instructions for all features. When the app is first run, pop-ups will be displayed indicating what the controls are used for. Warning: Blue Box is designed as an educational tool and utility. Do not attempt to use Blue for any illegal or malicious purposes. Blue Box can be used to assist in dialing numbers, but can not be used to manipulate digital telephone utility services. Limitations: Blue Box is software based decoding and is processor intensive. Performance may vary between devices. Tones that are less than 100 ms with pauses that are less than 100 ms are difficult to process in software. Future versions and processors may increase the reliability of faster tone sequences. If you need touch tone decoding for higher speeds, a hardware solution is recommended. Blue Box can not play tones into the iPhone phone feature while in a call. Blue Box is useful for entering numbers into touch tone operated systems such as an answering machine passcode or a dial-up service that requires the entering of several touch tones to navigate a menu system. Simply enter the numbers once and then play back the numbers into the phone's microphone with a touch.
DataLeft
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How much data is left? DataLeft answers on your Lock Screen — before you ever open the app. A calm gauge shows what's left of your plan and how many days it needs to last. If you're burning through data faster than the days, you'll see it in one glance — and get a heads-up before it's a problem. AT A GLANCE • Remaining data as a dual-ring gauge: data left vs days left • Widgets for Home Screen, Lock Screen, and StandBy • Alerts at 50 / 80 / 95% — helpful, never alarming BUILT FOR TRAVEL • Add your travel eSIM before you fly • Get a reminder to switch on arrival, and another before it expires • Fixed-period plans with D-day countdown PRIVATE BY DESIGN • No subscription. No server. No VPN. • Nothing leaves your device — there is nothing to collect • Works entirely offline DATALEFT PRO (one-time purchase) • Multiple plans — home plan and travel eSIMs side by side • Deep insights: 30-day trends, weekly rhythm, cellular vs WiFi • Daily budget alerts • Premium widgets Note: iOS provides device-wide network counters to apps. DataLeft shows accurate totals for your device; per-app breakdowns are not possible for any third-party app.
Screenshots
Verdict
The clearest difference is price: DataLeft at Free against Blue Box's $4.99. DataLeft also leads on update cadence (every 2 weeks vs every 7 months). Blue Box's advantage is in-app purchases (none vs 1) and device support (3 vs 1). On ads 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
DataLeft is free to download; Blue Box costs $4.99 up front. DataLeft sells 1 one-off in-app purchase. Blue Box asks for nothing beyond the download.
Blue Box ships an update every 7 months, DataLeft every 2 weeks. The most recent releases landed on September 30, 2026 and October 1, 2026 respectively.
| Parameter | Blue Box | DataLeft |
|---|---|---|
| Price | $4.99 | Free — better |
| Rating | 5.0 (3 ratings) — better | — |
| Positive reviews | 55.6% of reviews | — |
| Number of ratings | 3 — better | — |
| Update frequency | Every 7 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | — |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 15.0 — better | 18.0 |
| Further details — not scored | ||
| Size | 2 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Sunshine Valley Systems | Oh Hyeon Kwon |
In-app purchases
Blue Box
No in-app purchases
DataLeft
- DataLeft Pro$2.99









