I actually just rely on an RSS reader to present a whole bunch of ad-free headlines to me, and then I decide what looks interesting. The hottest topics are often covered by multiple, similar outlets, and then there are also niche publishers (like gwern, for example).
Almost unbelievably, on mobile my favorite feed reader is Pulse, which LinkedIn bought a year or so back. I've used Feedly, too, and Google's Newsstand, but Pulse seems easier to scan through.
For tech-specific news, HN is the best source to meta-news that's actually technical, as well as human curated weirdness. /r/programming, /r/technology, /r/android, etc are all good, too. Whenever there's a big trade show or launch event, I usually check Pando, TheVerge, UberGizmo and a few others (Re/Code, Mashable, VentureBeat, etc). I have an IFTTT recipe that pushes any new Android app disassembly article from Phandroid and Android Police (they do a FANTASTIC job of analyzing Google app updates for unspecified changes, and also always rehost the APKs). I look for in-depth product reviews from Anandtech. I laugh at XKCD's always timely cartoons.
Note that for the ones I follow via a reader, I almost never go to their site directly, and never see any ads. I do use an adblocker (uBlock), but I am considering uninstalling it because of memory consumption. I'm on a Chromebook most of the time and between Gmail & adblockers, 4GB of RAM just isn't sufficient.