Back then, the Adblock Plus was taken down as it goes against the advertising policy made by Google and especially for the Adblock Plus Browser. You could have installed Adblock Plus by sideloading it on Android and then making manual adjustments to the proxy according to the information from the app to get it activated. From my experience, the networking performance isn't that great with Adblock Plus activated on the Wifi hotspot I'm using. It also has disabled the functionality of certain parts of certain apps in which I can't see the notices, updates or whatever and the worse condition is that some of the secure web browsing proxies require that you have their apps active if you want to browse the net that way like the Orbot for instance, once you have its proxies entered on Firefox, you must have it activated or you can't browse at all.
The release of this web browser on IOS and Android is probably due to the support of extensions in Safari in IOS 9. I don't know if Safari on computers will support the same thing as well. It's a bonus opportunity for Eyeo to port their famous Adblock Plus to IOS 9 Safari web browser in addition to having released Adblock Plus Browser on both IOS and Android.
On Android, I think the best bet will be to have both the sideloading and Google Play Store methods as there may be less guarantee for the Android version to pop up in Play Store.
