Research In Motion Ltd., preparing to start sales of its BlackBerry PlayBook tablet, is working on software to allow the device to run applications for Google Inc.'s Android, three people familiar with the matter said. RIM plans to integrate the technology with the PlayBook operating system, giving customers access to Android's more than 130,000 apps, said the people, who asked not to be identified because the effort isn't public. RIM, after looking outside the company, is developing the software internally and may have it ready in the second half, two people said. By offering a tablet with the security and messaging of BlackBerry smartphones and the wide choice of Android apps, RIM may be able to woo customers who would otherwise opt for alternative devices, said Tero Kuittinen, an analyst with MKM Partners LLC.