You will need to use a Facebook or Twitter account to log in and test. They are on the free Meteor server and won’t be blistering in pace.
A link shortener that I made for sharing links with students. It doesn’t use any ambiguous characters like 1 or l and doesn’t care about uppercase and lowercase.
An app to learn some simple English, for Spanish speakers. Uses a spaced-repetition algorithm so when you revise your list, it doesn’t ask every question, just the important ones for today.
A simple app that uses the Twitter search API. For example, if you search for ‘sushi’ it will show any recent tweets in the city of Tuxtla Gutierrez (where I lived in Mexico), allowing a business to find new clients.