If you use a lot of productivity apps on iOS, the chances are one of them was made by Readdle. The Ukrainian company has built some of the biggest and best software for getting things done, including Spark, Scanner Pro, and PDF Expert.

Readdle launched its first app in 2007, just a few months after the very first iPhone went on sale. Since then, it has built 40 products and assembled a team of 135 people in eight locations around the world.

This week, Readdle hit a major milestone: 100 million downloads. Here’s how it happened.

Readdle, the team behind some of the best productivity apps and utilities for iOS, has slashed 50% off five of its top offerings for Black Friday. The sale includes titles like PDF Expert for iPhone and iPad, Calendars 5, and Printer Pro — all of which are now half price for a limited time.

Readdle has updated its popular Printer Pro app for iPhone, iPad, and iPod touch to introduce a new user interface that better fits iOS 7, as well as a number of new features. The app now promises “desktop class printing options,” such as the ability to print multiple pages on a single sheet of paper.

Readdle produces some of the best productivity apps money can buy for iOS devices, so it’s no surprise that it’s still going strong as it celebrates its sixth anniversary today. And in honor of this special occasion, the company has slashed up to 70% off all of its paid apps for a limited time.

It has also added a super cool timeline to its website that highlights some of the most important milestones and innovations from over the past six years.

Readdle, the developer behind some of the most popular productivity apps for iOS, has discounted a few of its best offerings for Black Friday. Some of which are down by as much as 80%, while PDF Expert for iPhone is now completely free. We’ve got a complete list of the reductions below, but remember: they’re only for a limited time, so grab the while you can.

One of our favorite applications this week is a great new photography app called Simply Postcards that lets you turn any photo into a real postcard that you can have printed with a personal message and mailed to friends and family.

Printer Pro is Readdle’s latest application for iOS, and one of the most impressive applications in our favorites this week. It allows you to wirelessly print a whole range of documents direct from your iPad, including email attachments, web pages, and iWork documents.

Also featured is a great language translator for the iPad, and the most definitive guide to Central Park for your iPhone.