Default Bluetooth hacking.

I have been searching for an app that can allow me to any bluetooth device. .came across a few apps but none of them really cut it for me. Finally I came across this app... Bluetooth file transfer..it did a great job @ hacking most bluetooth enabled devices(android nd Symbian phones). But at a point it stopped working and kinda messed up my normal bluetooth file transfers, still in search of an app that works flawlessly. Be kind to share your thoughts on any app you know that really hacks.