I've had the same problem myself before when I tried to connect my PC to my RPi 3. Basically what's happening here is that whenever your Pi connects to a device via Bluetooth, it checks if it can interact with that device. 

If it can't interact, the Pi will throw up an error and disconnect because there's no point in connecting to a device that you can't interact with. The likely reason the pairing worked with your colleague is that the RPi *can* interact with your colleague's BlackBerry, so the RPi won't throw up an error.

You'll probably have to make your program first, install it on your tablet, and *then* try to connect to your RPi, so it will see the program and not disconnect because of no available services.