Software developer Seesmic, maker of popular social media management smartphone apps, delivered stinging news to Canadian-based smartphone maker Research in Motion, Ltd. (TSE:RIM), commenting in a blog post:

Effective June 30th, Seesmic will discontinue support for Blackberry in order to focus development efforts on our most popular mobile platforms: Android, iOS and Windows Phone 7.

While normally it would be foolish to microanalyze app defections, this was merely the latest development in a broad trend of top developers abandoning RIM this year.  Bloomberg reports that Purple Forge Corp., a maker of political campaign an polling apps, will drop general support for the platform, offering it only if clients specially request it.  Likewise, Mobile Roadie LLC, which makes apps for fans of the Miami Dolphins and country singer Taylor Swift, says it is ditching support for Blackberries.

Reportedly one key factor is that developing for RIM handsets is complex, thanks to a large amount of hardware inputs and a less than modern API that fails to match the ease of Google Inc.'s (GOOG) Android, Apple, Inc.'s (AAPL) iOS, or Microsoft Corp.'s (MSFT) Windows Phone 7.

Purple Forge CEO Brian Hurley reflects this, commenting, "As soon as RIM brought in a touchscreen and mixed it with a thumbwheel, a keyboard and shortcut keys, it made it really difficult and expensive to develop across devices. What Apple scored big on is having a touch screen and a button and that’s it. In deploying Apple applications, there are very few surprises. In Android, there are increasingly more surprises. But in BlackBerry, there are immediately lots of gotchas across the board.”

Like struggling Finnish phonemaker Nokia Oyj. (HEL:NOK1V), RIM is counting on an OS change to reverse its fortunes.  In early 2012, it will switch to using QNX's operating system in its new smartphones.  RIM's first QNX product was the PlayBook tablet, released in April -- a year after RIM acquired the small Canadian OS maker.