iRig 2 – Turn Your Phone Into a Guitar Interface
The iRig 2 plugs directly into the 3.5 mm port and lets you feed a guitar or bass signal into iOS or Android music apps such as GarageBand. It works as a line‑in, an audio interface, and a multi‑effects processor, making a full studio chain portable.
- 3.5 mm TRRS connector
- Compatible with iPhone, iPad, Android, and older iPods
- Supports real‑time amp modeling and effects
Square Card Reader – Mobile Payments via the Aux Port
Square’s tiny chip‑card reader fits into the headphone jack and pairs with the Square Point of Sale app. It lets you accept swipe, chip‑and‑pin, and contactless payments wherever you have internet access.
- Plug‑and‑play with any phone that still has a 3.5 mm jack
- Works with Square, Walmart Pay, and other POS software
- No extra Bluetooth or USB dongle required
Smart Geiger Pro – Pocket‑Size Radiation Detector
Designed for Android phones, the Smart Geiger Pro uses the headphone jack to power its semiconductor sensors and report gamma and beta radiation levels through a companion app.
- Measures radiation with ~15 % margin of error
- Four built‑in sensors for quick readings
- Ideal for science demos, hobbyist checks, or field scouting
ServoDroid – Motor and LED Controller
ServoDroid connects to the aux port and provides a visual drag‑and‑drop interface for controlling up to eight servos and eight LEDs. No coding is needed, making it perfect for rapid prototyping.
- Jack‑to‑jack cable for Android or iOS
- Graphical app lets you create sequences, loops, and triggers
- Great for camera rigs, light shows, or small robots
EVP Microphone – Ghost‑Hunting Audio Capture
The EVP microphone is a dedicated X/Y stereo mic that plugs straight into the 3.5 mm jack. It records a wide 100 Hz‑15 kHz range, capturing the subtle sounds paranormal investigators call Electronic Voice Phenomena.
- Dual‑channel X/Y stereo configuration
- Compact, plug‑and‑play design
- Optimized for EVP detection software