The REETLE SmartInk I is a phone case with a touch-enabled E-Ink display and built-in AI features. It features a secondary screen on the back for reading text, viewing notes, recording voice, and displaying to-do items, allowing basic tasks to be completed without using the phone’s main display.
In the back, you have a 3.97-inch E-Ink touchscreen with one-press voice recording, AI-based transcription, summarization, and smart to-do display, all synced to a companion mobile app via Bluetooth 5.0. It supports iPhone 13–17 series and a wide range of Android phones, features a 300 mAh battery with 10W MagSafe wireless charging, and delivers up to 10 hours of reading, 8 hours of recording, and over 2 weeks of standby time. Weighing around 55 grams with a total thickness under 4 mm, it includes military-grade drop protection, tempered glass, widget switching (QR codes, notes, schedules), a thin design, and a 10°C to 55°C operation temperature range, making it suitable for meetings, interviews, reading, journaling, and on-the-go productivity use.
REETLE SmartInk I (ETS 1301 model) specifications:
Compatability
iPhone 13 to iPhone 17 series
Android smartphones (model support via companion app)
Display – 3.97-inch, 480 × 800, 235 PPI E-Ink touchscreen
Touch interface
Capacitive touch panel
Operated via onboard touch input and mobile app
Wireless Connectivity – Bluetooth 5.0
Audio – Built-in microphone for audio recording (up to 8 hours)
Misc
On/Off button (supports gestures)
Record button for recording audio.
Up to 10 hours of active use
Over 2 weeks of standby time
AI Features – Transcription, summarization, smart to-do sync
Power
300 mAh rechargeable lithium battery
10W wireless charging for the 300mA battery
Dimensions − 152 × 74.5 × 12.5 mm (L × W × H)
Weight − 55 grams
Operating Temperature − 10°C to +55°C
Build − Tempered glass, military-grade drop protection
Software support is provided through a companion mobile application for iOS and Android, which handles device pairing, content synchronization, voice recording, and AI-based transcription and summaries. The app is used to configure widgets, manage notes and to-do lists, and push selected information to the E-Ink display over Bluetooth, while the SmartInk I itself operates as a low-power secondary screen without running standalone applications.
The REETLE SmartInk I can record audio non-stop for up to 8 hours in a single session. This assumes sufficient battery charge and no manual stop of the recording. After ~8 hours, recording will stop due to battery limits or internal file limits, and the device will need to be recharged or restarted before recording again. Captured audio is sent immediately to the companion mobile app on your phone via Bluetooth. Once the audio reaches the phone app, the AI processing (transcription, summarization, key-point extraction) happens there or in the cloud, and the results are stored or managed within the app’s data.
Previously, we wrote about the YotaPhone 3 back in 2017, which featured a 5.2-inch E-Ink display integrated into the phone itself, so the concept is not entirely new; REETLE SmartInk I applies a similar idea by implementing it as a phone case rather than a dedicated handset. We have also written about other Android smartphones and tablets with color E-ink displays like the Bigme HiBreak Pro, the Onyx BOOX Tab, and others.
REETLE SmartInk I Basic Kit
Some of the Android smartphones supported by the REETLE SmartInk I case
The REETLE SmartInk I is currently available on Kickstarter with worldwide shipping. Pricing for a single unit is $119 US for Super Early Bird backers, $149 US (Early Bird), and $169 US (Kickstarter Special), which will increase to $199 US retail. The product is available in iPhone-specific and Universal variants (for most of the Android phones). According to the project timeline, mass production is scheduled for January 2026, with shipping expected to begin between February and March 2026.

Debashis Das is a technical content writer and embedded engineer with over five years of experience in the industry. With expertise in Embedded C, PCB Design, and SEO optimization, he effectively blends difficult technical topics with clear communication
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