(From John Clark)
If you've upgraded to OS 10.2.1.x on your BB10 device you can now install any free Android app directly to your BB10 smartphone directly without any special converting and without the need to connect to your PC. This opens up BB10 to the thousands of Android apps available in the Google Play store. However, you need an app to quickly search for and install these Android apps.
The best app available so far is called Snap. Unfortunately, Snap can't be installed directly to the device since it's a native BlackBerry app and is not yet available in the BlackBerry App Store. However, it can be quickly loaded to your BB10 device using your PC.
Here is a quick and easy way of installing Snap on your BB10 device using your PC. Once Snap is installed on your device you won't need your computer to install Android apps on your device!
1. Download Sachesi for your computer Platform, i.e. Windows, Mac, Linux (Don't download the Sachesi bar file for BlackBerry or the apk file for Android)
Sachesi
2. Download Snap from here:
Snap
3. Connect your BB with the USB cable.
4. Double click on the Sachesi app you downloaded.
5. When it opens, click the "Install" tab. (If your device requires a password enter it here.)
6. Drag the Snap bar filed you downloaded in step 2 into the box under the install tab. As soon as you drop the file it will load to the device.
7. That's it! You can disconnect your device and enjoy direct downloading of Android apps on your BB10 device by opening Snap and using your Google Account.
Note: Not all Android apps will run on the BB10 and, occasionally, an app will not work quite as expected. However, the vast majority do run normally.
Credits:
Sachesi:
http://forums.crackberry.com/bb10-leaked-beta-os-f395/sachesi-firmware-extractor-searcher-installer-...
Snap:
http://forums.crackberry.com/bb10-android-app-sideloading-f279/snap-download-apps-google-play-direct...