This is a highly-customizable email assistant developed mainly for power users who receive over 200 emails a day. Overview Emailio is a Y-Combinator company from Bulgaria that was developed in collaboration with Professor Dan Ariely (named one of the 50 most influential living psychologists in the world), based on principles of attention, procrastination, and efficient use of time. This product utilizes an advanced set of filters and displays the emails to the user according to their importance. The key feature of Emailio (the swipes) required a really sophisticated custom UI implementation that was developed from scratch and only for this app. Swiping was still uncommon at the time. We implemented an independent syncing system specially designed for the purposes of the application. The client had lots of ideas, most of which were very complex and required custom implementation. We decided to rewrite their existing app entirely from scratch because its old architecture had too many flaws and we used Swift although this programming language had just come out. What we ended up with was one of the most innovative email clients for its time.