Pushover is a pushnotification site that just gives you an API to work with and a near-universal app that runs on Android or iOS. Add realtime notification to whatever you want with nearly no work. The app's free for a week; after that you have to pay $5us for a perpetual license. You also get 7500 notifications per month per integration.
An openstreetmap app for android which keeps tabs on your GPS coordinates and shares your location in an anonymous fashion with a random Target ID and tracking code. Can share with chosen people or the public at large. Can transmit and receive data via SMS.
A personal webapp for tracking your own location. Lets you set up a private location diary or a realtime tracker to share with people you give access to. A phone app for iOS and android is the user front-end. The app can publish GPS coordinates and your phone's status to an arbitrary HTTP API endpoint or MQTT broker if you tell it to. Your location gets plotted on a map. The back-end is called Recorder and is found on github: https://github.com/owntracks/recorder
FOSS AI personal assistant software. Implements actions/useful features, skills and API connectors. Can answer questions and ask for context for better answers (interesting!) Has a dedicated android app as well as a web interface. Written in Java, but nobody's perfect.
voice assistant speechrecognition exocortex Designed for privacy, runs on-device on-prem, works without a network connection. There are community contributed skills, called snips, provided skills, and you can develop your own with a web based visual builder. Supports multiple human languages. Deploy to your own devices as long as they run android or linux. github repos here: https://github.com/snipsco
A crowdsourcing service which lets lets people who are visually impaired call for visual assistance from their smartphones.