Digital Turbine's Ignite is here to light the fire of your bloatware-gripe anew
And why do carriers do that, you ask? Well, sponsorship is the answer – the best way for a developer to advertise their app is to have it pre-installed on brand new phones, and to have it reinstall itself if a device just so happens to be factory reset and re-sold on the second-hand market. For this, they pay the carriers. Understandable – business is business, but when your customers' user experience is threatened, things start going astray.
It's provided by Digital Turbine and is called Ignite. What it does is, it not only allows carriers to install bloatware on new devices without requiring the help / approval of phone manufacturers, it will also let them install apps post-sale, via over-the-air updates. As opposed to regular bloatware, these post-sale installed apps will be user-removable... but – if you restart your device, DT Ignite will re-install them. Users report that their handsets did not even prompt them on whether they wish to install new apps – which would mean that Ignite bypasses Android's app security.
So far, it is known that this “service” is being employed by T-Mobile and Verizon, with the Ignite app being pushed to devices with an OTA update. If you wish to rid yourself of potentially unwanted app installs – go to Settings → Apps, and look for DT Ignite. If you have it, disable it (you can't uninstall it unless you are rooted – but we can't say we are surprised).
source: Android Authority, Reddit via Android Community
Things that are NOT allowed: