When I reviewed the first BlackBerry 10 smartphone, the Z10, in January, I had mostly good things to say but also expressed concern that big-name app publishers were not throwing their support behind the new platform by building BlackBerry 10 apps. Since then, a number of notable companies and organizations released BlackBerry 10 apps or ported over Android versions of their software, including Amazon (Kindle), Cisco and eBay, to name a few. \n\n\n\nBlackBerry Q10 and BlackBerry Apps\n\nUnfortunately, many of these companies' BlackBerry 10 apps are not yet compatible with the new BlackBerry Q10, which raises a new software-related issue for BlackBerry: Not all BlackBerry 10 apps are compatible with all BlackBerry 10 smartphones. (The BlackBerry Q10 is currently available in the United Kingdom and Canada, and it is expected to be released in the United States starting in late May.)\n\nI recently wrote about the differences between native BlackBerry 10 apps and "ported" Android software for BlackBerry 10, stressing that not all BlackBerry 10 apps are created equal. The lack of Q10 support in many current BlackBerry 10 apps, native or ported, could raise this app issue to another level.\n\n\n\n\nAnd BlackBerry is making the problem worse by promoting apps on Twitter and other social-media sites without clarifying that "available for BlackBerry 10" does not necessarily mean "available for both the BlackBerry Z10 and Q10."\n\nFor example, the following tweet was posted by @BlackBerry on Twitter earlier this week:Digital bookworms, rejoice. The @amazonkindle app is available for #BlackBerry10: blck.by\/Z6qVei\u2014 BlackBerry (@BlackBerry) April 29, 2013\n\n\n\nAs I soon as I received my Q10 review unit, I went to download the Amazon Kindle app and all of the BlackBerry 10 apps I use on my Z10, only to find that more than half of them, including Kindle, are not compatible with the new device - not yet at least. \n\nI reached out to BlackBerry with a list of the Z10 apps that aren't compatible with the Q10, and I was pleased to see that the majority of them are expected to be Q10 compatible soon, so the issue may prove to be less notable in time. But here's the list I sent, along with responses from BlackBerry. (ETAs from BlackBerry are in italics.)\n\n Amazon Kindle (First week of May) \nBlackBerry Travel (First week of May) \n BeWeather (End of May\/Early June) \n eBay (End of May) \n OpenTable (End of May) \n GoMusic, Google Music clien ( No date set) \n Charge Anywhere Mobile Payments (early May ) \n Amazon Shopping (Early to mid-May) \n Pacemaker (No date set) \n Google Talk ( No date set ) \n StubHub (end of may) \n Cisco WebEx (End of May) \n Truphone (this week) \n Gadget Box (No date set) \n\n\nMarty Mallick, BlackBerry's senior director of strategic business development told me, through BlackBerry PR, that "many partners are timing their launches to the regional launches around the globe similar to the Z10 launch, so we will see more brands launch their apps closer to US availability."\n\nI also sent a list of popular Z10 games that are not available for the Q10, but BlackBerry did not send any expected release dates for that software, which suggests it may be some time before they make it to the Q10, if they do at all. It appears that the Z10 will be much more game-friendly than the Q10, which makes sense given its larger display. (The games I asked about include Magmic's Blackjack King; Gameloft's The Amazing Spiderman and The Dark Knight Rises for BlackBerry 10; and Monopoly for BlackBerry 10 from Electronic Arts; all of which are top-grossing BlackBerry 10 games in BlackBerry World.)\n\n\n \n \n \n \n \n\n \n\nKisai Labs' Jerome Carty, a noted BlackBerry 10 developer and a creator of the popular Blaq for BlackBerry 10 Twitter app, provided some insight on BlackBerry 10 development. (Blaq is currently one of the top 10 highest grossing BlackBerry 10 applications in the BlackBerry World store, and it is compatible with both the Z10 and the Q10.)\n\n\n\nCarty says he didn't have to do much heavy lifting to make Blaq compatible with both the Z10 and Q10, but that other developers may fare differently if it's a game and whether or not it's native or ported over from Android.\n\n"Currently, the main differences [between the Z10 and Q10] are screen sizes (768x1280 vs. 720x720) and the physical keyboard of the Q10, which provides keyboard shortcuts," Carty says. "[U]nless its a game, it should really take little to no time to have an app ready for both. Different tools arent required. Once you get over the hurdle of smaller real estate, its not so bad. That has been my only issue thus far."\n\nBlackBerry said in the past that it will release three tiers of BlackBerry 10 devices. Each tier will have one all-touch device and one "physical" QWERTY keyboard. The Z10 and Q10 represent the high-end tier, but BlackBerry has not yet announced any of the mid- or low-end devices. (Images of the rumored mid-range device recently leaked.)\n\n\nAs far as Carty knows, the three all-touch devices will have the same 1280x720 resolution and the full QWERTY handsets will all have 720x720 resolutions, so development tweaks will not be necessary whenever a new device is released.\n\nIf the process of making BlackBerry Z10 apps work on the Q10 is so simple, why are so many apps still incompatible with the new device?\n\n"I'm as curious as you are," Carty says. "This is pure speculation, but in some instances, those apps are Android apps and it's possible they weren't made to fit square screens as well, so adjustments may need to be made.\n\n"It makes sense for all BlackBerry 10 developers to make their apps compatible with both touch and QWERTY handsets simply because it requires almost no effort to support both. The main exception is always a game, but with a full keyboard there are creative ways to go about the experience that developers may or may not enjoy."\n\nOnly time will tell if app fragmentation within BlackBerry 10 will become a significant issue, but one thing is clear: BlackBerry Q10 owners may have a more limited app selection than Z10 owners, and potential buyers who want the most possible applications may want to weigh their options before picking the Q10 solely because it has a QWERTY keyboard.\n\nAS\nAl Sacco covers Mobile and Wireless for CIO.com. Follow Al on Twitter @ASacco. \n\nFollow everything from CIO.com on Twitter @CIOonline, Facebook, Google + and LinkedIn.