Here some little known, yet awesome apps or tools that I use. Thanks to the people working on these (I’m glad to have met some of them, and they’re awesome too)!
Transportr is an Android app to help you use public transports systems. It’s simply the best one I’ve seen, and it supports a lot of systems (city-wide like Berlin or Paris and even long-distance).
Known (formerly “idno”) is more “socially aware” than ikiwiki. It runs with PHP and it’s basically your easy-to-run indieweb space. If you use it with http://brid.gy you will enjoy a nice integration with twitter and other silos (see an example of my own).
YunoHost is custom debian distribution aiming at making self-hosting easy. It provides a nice web interface for administration of your self-hosted server and for users of the web server. If you have basic linux administration skills, this will be very helpful.
Sharesome lets you easily share files on the web. It has a pleasant interface that works well on all devices I have tested so far. It’s also available as a web app. The neat feature is that you can choose where to host your data (for instance, with remotestorage; you can get an account at https://5apps.com).
Some shameless self-promo with ToSDR, the app that tells you what happens to your rights online by rating and summarising Terms of service and privacy policies. You can also get it directly in your web browser or as a web app.
If you’re looking for a curated list of awesome web services that are free of charge and based on free software and open data, look no further than Jan’s Libre projects.