Thermal Printer · Pocket Printer
Anything on your screen, on paper in seconds.
A companion for pocket Bluetooth thermal printers: send a photo, a signature, a magic square or a clock face straight to a 58 mm or 80 mm printer — dithered, previewed and checked before a single line is fed.
- Requires
- iPhone with iOS 15.0 or later, or an Android device with Bluetooth LE.
- Languages
- English, 简体中文, 繁體中文, 日本語, 한국어, Español, Français, Русский, Bahasa Indonesia
Thermal Printer turns the phone in your pocket into a printing press. It speaks Bluetooth LE to the portable printers magicians, market stalls and workshops already own, and it handles the part those printers will not do for you: turning a colour photo into the black-and-white dot matrix a thermal head can actually burn.
A thermal head has exactly two states — dot or no dot — so every picture has to be converted first, and the conversion is where most printing apps give up. Here you get fourteen dithering algorithms, four scan orders and a strength slider, with a live preview of the strip you are about to get. When it looks right, print it: the app checks paper and cover first, keeps you posted on progress, and out comes a sheet you can tear off and hand over.
Photos are only the start. There is a handwriting pad with smoothed strokes, a clock that prints its hands at the time you choose, a magic square generator, and a font editor that compiles your own letters into a real typeface before printing with it. The same engine can be driven from outside the app through the thermal-printer:// URL scheme, so another app or a web page can hand it an image and let it print on its own.
What makes it different
Prints from your pocket
Talks Bluetooth LE to the 58 mm and 80 mm thermal printers you already own — no cable, no driver, no account.
Fourteen dithering algorithms
Atkinson, Floyd–Steinberg, Stucki, Burkes, Sierra, Bayer and more, plus four scan orders and a strength slider, so gradients survive the jump to a two-state print head.
Handwriting that still looks hand-made
Smooth strokes on a plain white pad. Write a prediction or a signature, print it, and what comes out is what you drew.
Your own typeface, printed
Draw each character, add OpenType variations, and the app compiles them into a real font you can lay out and print immediately.
Checked before it feeds
The printer is asked for its status first: no paper or a lifted cover stops the job before a single line is wasted.
Driven from other apps
The thermal-printer:// URL scheme accepts a local path or an image URL and can print automatically — a web page can call it.
Everything inside
- Bluetooth LE discovery, with up to three known printers restored automatically.
- Switch printers in a tap. Paper width — 58 mm / 384 dots, 80 mm / 576 dots — is remembered per device.
- Device details on hand: model, firmware version, MAC address, serial number and battery level.
- Print density in three steps, auto power-off from 5 to 60 minutes, and an optional continuous feed after each print.
- Fourteen dithering algorithms with four scan orders (raster, serpentine, diagonal and Hilbert curve) and adjustable strength.
- A live preview rendered at the printer’s real dot width before you commit to paper.
- Status pre-check plus an unmissable progress dialog — out of paper or an open cover is caught in time.
- A command test screen for sending raw ESC/POS instructions whenever you need to debug a printer.
- Photos from the gallery, or pushed in from another app through the URL scheme.
- Handwriting: a white pad built for predictions, notes and signatures.
- Clock: pick a dial face and a time, and the hands are rendered as dots.
- Magic square: enter a total and get a 4×4 square whose rows, columns and both diagonals all add up to it.
- Custom font: draw A–Z, a–z, 0–9 and punctuation, keep twenty variations of each, and print with the typeface you just made.
How it works
Connect
Switch the printer on and pair it once over Bluetooth. It reconnects on its own from then on.
Choose the content
A photo from the gallery, a drawing, a clock face, a magic square, or a line of type in your own font.
Tune the dots
Cycle through the algorithms, scan orders and intensity until the preview looks like the paper you want.
Print
Paper and cover are checked, then the strip feeds through while the progress dialog keeps you posted.
Tear it off
The continuous feed leaves a clean margin to tear along. Hand it over — nothing about it looks digital.
Getting better prints
- High-contrast artwork survives dithering best. A busy background turns to mud on a 384-dot head.
- Atkinson keeps portraits light and airy; Floyd–Steinberg holds more detail in logos and line art. Try both on the same image.
- Check the battery indicator before a run of prints — on low power the far end of a long strip fades.
- Match the paper setting to the roll you loaded. 80 mm content sent to a 58 mm printer crops the right-hand edge.
Get the app
iOS
v1.0.0iPhone with iOS 15.0 or later, or an Android device with Bluetooth LE.