Giyo GM-43BT CNC Super Mini Pump allows pressure to be read using your smart phone (requires Bluetooth 4.0 + Free iGauge app).
This compact pump measures just 135mm x 28mm and weighs 138 grams (inc. plastic mounting bracket).
CR2032 battery included.
*Free iGauge app available on App Store and Google Play. Supports iPhone4S and Android 4.4 or later.