The simplest way to make any app print: turn Bluetooth Printer+ into a normal Android printer, so any app's native Print button can use it - Chrome, Gmail, Google Docs, Files, anything with a "Print" option.
📸 Screenshot: Android Settings → Printing, with "Bluetooth-USB Printer +" toggled on
What it is
Bluetooth Printer+ registers itself as an Android Print Service, the same system used by AirPrint-style network printers. Once enabled, it shows up as a destination in the standard Android print dialog (the one you get from Chrome's ⋮ menu, Gmail's print action, Google Docs, etc.). No app changes, no SDK, no code - this is an end-user/OS-level integration, not an API you call.
Unlike the other six integrations in this guide, Print Service doesn't receive raw text from you - it receives a fully-rendered page (Android converts whatever the source app is showing into a print-ready image), which Bluetooth Printer+ then dithers and sends to your thermal/label printer.
Setup
Turn on Bluetooth and pair your printer inside Bluetooth Printer+ as usual.
On the phone: Settings → Connected devices (or Apps) → Printing → enable "Bluetooth-USB Printer +".
Open Bluetooth Printer+ → Settings → Print Service Settings → Select Default Printer → choose your paired printer.
Pick the correct paper size (58mm / 80mm / labels / continuous roll) in Print Service Settings - this is what the incoming page gets scaled to fit.
From any app, tap Print and choose "Bluetooth-USB Printer +" as the destination.
📸 Screenshot: in-app Print Service Settings screen (default printer + paper size picker)
Examples
Plain text
Printing a plain .txt file or a simple note from the Files app / a text editor's Print action - one paper size, one font, no styling.
📸 Screenshot: system print dialog with "Bluetooth-USB Printer +" selected, printing a plain text note
Rich text
Printing a formatted Google Doc, an email, or a web page with bold text, tables, and images. Because Android's print framework renders the whole page as a raster image before handing it to the print service, formatting, tables, and inline images come through automatically - Bluetooth Printer+ just dithers and prints what it's given.
📸 Screenshot: a formatted invoice/Google Doc printed via the system dialog, showing bold headers and a table intact
Placeholder
Not applicable here. Bluetooth Printer+'s [[placeholder]] / #[[placeholder]] template system only applies to content sent directly into the app (Intent Printer, Deep Link, or typed in the Editor/List). Print Service prints exactly whatever the source app already rendered - there's no template layer in this path.
Limitations
Must be manually enabled once per device in Android's own Settings → Printing menu - there's no way to enable it silently/programmatically from another app.
Uses a single default printer set in Print Service Settings, not whichever printer happens to be connected in the main app at that moment.
Paper size must be configured up front (58mm, 80mm, label sizes, continuous roll) - content is scaled to fit that size, not auto-detected per job.
No [[placeholder]] support - see above.
Large/complex pages (multi-page PDFs, high-resolution images) take longer to render and dither before printing starts.
If the printer service isn't listed, it may need a manual re-enable via adb shell settings put secure enabled_print_services com.iyaltamizh.app.btprinter/.AndroidBluetoothPrintService.