Still pretty excited about our last year success, Jordy Langen and I again joined the Droidcon conference in London. For those who missed out: we won the first prize at the Droidcon hackathon with our Zebra Laser Tag App in 2016. This year, we were accompanied by Android freelancer Boy Lenssen and Christian Langer from Axessio, with whom we are working on Deutsche Telekom projects. Armed with a group of 4 suckers for Android, we were hyped for this amazing 2-day conference. A must go for Android software developers.


Arriving at the venue, we were remembered on their last year’s promise. The big hall had been transformed into the main speaker room, meaning that they upgraded from 4 to a whopping 5 simultaneous rooms/tracks filled with sessions throughout the two days. In the main hall, the theme of this year was immediately noticeable (and hearable); drones! In the middle of the hall, drones were flying around and showing off their tricks. Beneath all this was the area for the sponsor stands, drinks, food and not to miss: ping pong tables! Having a ping pong table in the Mediaan office, we couldn’t resist having a go right away.

Day one

Android, a retrospective

After a quick introduction by the awesome organization, Droidcon started off with the keynote “Android, a retrospective” about the history of Android. Chet Haase and Romain Guy gave this talk and it was very interesting to look back upon the very start of Android and how it matured over the first years into being the biggest mobile platform OS it now is. Of course, this talk had some humour in it as well (Chet being Chet), showing regret on some decisions made in the past (Fragments anybody?).

Machine learning and AI

Another good session of the day contained the subjects Machine Learning and AI. A hot topic, which has found its way into mobile as well. Not only for usage in the backend but locally on the (Android) device with e.g. the recently released TensorFlow Lite.

Saying hi to Zebra

Next to the sessions, we had a walk in the main hall to see the sponsor stands: Android Things, Facebook, Amazon, XDADevelopers and the lesser known (or more local) sponsors as well. Zebra Technologies also had a stand, so of course, we paid them a visit. Catching up with some familiar faces from the hackathon last year and our collaboration with Zebra this year. Having our Laser tag app released this very same day was exciting to all of us.

Closing the first awesome day

To close the day, a party was organized in the hall after the last sessions. With food, beer and another round of ping pong, this was the perfect ending to the first day. But to make it even better, we’ve made a reservation (3 week before) to visit the Sky Pod Bar at the Sky Garden. Enjoying some cocktails, we enjoyed the view over London with the Shard across the Theems and the London Tower Bridge to the left.

Day two

Comedy show

After a very good breakfast at “The breakfast club”, we were ready for the Friday of Droidcon. Again Chet Haase and Romain Guy had a big talk, but this time it was purely comedy. With their own programming language F.A.R.T. they would replace the need of all other languages. It was amazing to see all the jokes they had come up with and their epic replies to the audience’s questions.

Facebook Litho

Another great talk was from Facebook about Litho. This library created by Facebook does some very nifty view recycling, which should be more performant than the normal view recycling on Android. View recycling is a smart thing that happens on a list of items when you scroll. Items that move off-screen won’t be thrown away but kept in memory and are recycled as new items that appear on the screen. This makes sure you only need to change some text or the image of that list-item and not completely recreate it from scratch. Facebook’s Litho went a step further and recycles separate views inside your list-item. Last year they showed it as well, and this year their talk was more in-depth.

Going deep into the code

To close the second day, we joined the session of Jake Wharton on Bytecode. Going deep into the code that’s compiled out of Java and Kotlin code to have a look into the bytecode that’s produced. Jake Wharton formerly worked at Square but has now joined Google and is a well known guy in the Android scene for his libraries and Kotlin knowledge from the early days. His session was very interesting and showed us what happens after we’ve written and compiled our code.

Meeting the Dutchies

During the day we had a meet-up with all the Dutchies from DutchAUG (the Dutch Android User Group). This is a community which hosts interesting meet-ups about Android topics. Having our Slack channel hot with messages from everybody spread throughout the sessions/tracks, we decided to gather everybody who were attending Droidcon. Having a group of 15+ people, unfortunately not everybody made it on the picture. But hey, shoutout to the DAUG’s being at Droidcon in London

Overall session topics

Next to the highlighted sessions above, there were of course a lot of other sessions. General hot topics were RX (Reactive Extensions),  UI (User Interface) and UX (User Experience) security, testing and of course Kotlin with big names like Chris Banes, Nick Butcher and Jake Wharton. What we noticed is that Kotlin wasn’t treated anymore as something special, something unknown to the general public. Since its “approval” by Google at their I/O event this summer, Kotlin has become the new and accepted programming language for Android. A lot of the talks that weren’t specifically about Kotlin still used Kotlin code instead of Java. And the speaker didn’t even mention it. Cool to see this new development in the Android world!

The weekend (Droidcon2gether)

Last year, there was a hackathon during the weekend where several sponsors had put out a challenge for us. This year it, unfortunately, wasn’t a real hackathon anymore. Nonetheless, it was an interesting weekend. One of the sponsors, XDADevelopers, had a workshop on the Xposed framework where you could alter the normal behaviour of your Android phone/apps with these modules.

The coolest workshop was organized by Google on Android Things. This is a version of Android which is meant for Internet of Things devices (hence the name), like a Raspberry Pi or some Intel or NXP boards. Google handed out a free (!!)  “Pico Pro Maker Kit” to everybody. This contained an NXP board, a 5” touchscreen display, WiFi antenna and the RainbowHAT shield. After assembling, also part of the workshop, we made a weather station and a smart doorbell using the sensors, LEDs, display and touchscreen.


In the end, Droidcon London was once again a great conference to attend. There were so many sessions with good topics that’s it’s actually a pity we couldn’t attend all of them. Also, London itself is super nice and the weekend got fun too with Google’s Android Things workshop. We will definitely return to Droidcon London next year.

Recorded sessions

Check out the program of the two conference days, and even better: most of the sessions are recorded.