PINT is an innovative app that trains both your ear and your instrumental skills

While you can use PINT as a standard multi-temperament tuner and tone generator, an innovative function allows you to check your intonation by ear against a fixed drone of your choice.

You can choose the height of the drone (the fundamental of the scale), the octave, the base "A" pitch and the temperament: PINT will recognize the scale step you are playing and check your intonation against the selected temperament.

AUT - Auto USB Tether is an utility app that automatically activates your USB Tethering functionality whenever you connect your device to a PC/Mac through an Usb cable.

Gianluca Barbaro (AUT's Developer):
I decided to develop AUT after unsuccessfully trying the 10+ apps on the Play Store that claim to do what AUT does. None of them worked on my device or they were too complicated to use. Auto-activation of Usb tethering is not supported by the Android system, so it's not a surprise that those apps didn't work. It is a complicated matter from a developer's stand point.
With AUT I tried a different approach: auto-detection of the necessary parameters. It's not guaranteed to work on any device, but it definitely has more chances than apps with hardcoded parameters. Give it a try!

AUT can also show the current USB In/Out networking traffic and (attempt to) hide your tethered traffic from your carrier.

Zanzito is an app that acts as a bridge between your Android phone and an MQTT server. MQTT is a lightweight means of communication between systems, such as your home automation system and the various sensors and hardware devices in your home.
The MQTT protocol is based on the principle of publishing messages and subscribing to topics, or "pub/sub". Multiple clients connect to a broker and subscribe to topics of interest. Clients connect to the broker and publish messages to topics.