By now we expect most manufacturers and carriers to be releasing updates to Android 4.0 Ice Cream Sandwich and not maintenance updates. However, this doesn’t seem to be the case for the HTC Thunderbolt, which was one of the devices in HTC’s guaranteed list of getting Android 4.0.
According to AndroidPolice, an HTC Thunderbolt maintenance update 2.11.605.19 has been leaked for the HTC Thunderbolt, but it only carries bug fixes and stability enhancements to Mobile Hotspot, Yahoo Mail, and VZW Navigator.
The update still includes Android 2.3 Gingerbread and HTC Sense version 2.1. If you’re willing to give it a go, be sure to hit up the source link below.
Source: Android Police