Unfortunately we are unaware of any monitoring or filtering software for webOS devices at this time.
HP webOS internet-proofing your device
For the few of you out there still using HP webOS (formerly Palm), here's the only way that we know of to internet-proof your device since there is currently no monitoring or filtering software available. This will not harm the functionality of the phone's other applications and processes. The process isn't necessarily elegant but it works. The solution is to cripple the browser app altogether: