Github Apps are a nice way to automate some of the complicated or boring tasks in a version control workflow. At the moment it's in Early Access so the documentation is a bit sparse and the functionality is incomplete. Still it's possible to do some cool things.
The Environment Agency has a really cool rain data api which I've used in a little react app. Just a simple display of the rain data so you can check what the water levels in caves are going to be like.
More apps caving programming
Quick description of how to get celery running on two different apps with two separate queues on the same RabbitMQ instance.
simple-ddns is a lightweight home made dynamic dns program.There is a little flask application that can be run on a VPS to keep track of something elses IP address (a home network for example). It can also edit an nginx configuration to redirect a subdomain or url to the ip. An included python script can be used on the client (via cron job or manually) to update the flask app.