A while back we took at look at a tool called BarInstall that allows you to install BAR files (aka sideload apps) to your BlackBerry 10 device without the use of a Mac or PC. The app requires a premium account at which point you can upload a BAR or APK file and easily sideload to your device OTA.
A new version has been released that is sporting Localbar mode - essentially a free way to install BAR files to your device from your SD card, albeit with a bit of work. You'll need to setup a proxy using a computer, Android device or even an old BlackBerry, but then you can install any BAR files from your SD card without the direct use of a computer.
CrackBerry is in no way Affiliated with BlackBerry. We take pride in our unbiased content, however do occasionally receive free products from vendors that we review or discuss. For more info click here.