Pretty sure you're talking about the list of "Z" apps that are found on development handsets. Your phone is not a retail model, instead it was built for OS and firmware testing. It is like a retail one in most ways - that is to say, it can probably be used as a phone - aside from the following:
1) Whoever sold it to you probably stole it (or got it from somebody who did) since they aren't supposed to be sold in stores.
2) It probably doesn't *quite* run a released version of the OS, so it may have bugs that were fixed later.
3) It may not be possible to update it using the retail update channels.
On the more exciting side, though:
1) It should support USB Mass Storage mode in the bootloader. This means you can access it exactly like a flashdrive (but hold on...)
2) It should have an unlocked boot loader (no Secure Boot) so the OS can be modified.
3) It'll have a bunch of internally-developed apps meant for testing, many of which will have unusual privileges.
4) The phones should support kernel (and other high-privilege) debugging.
Such handsets are rarely seen (since they aren't ever officially sold) and are pretty useful to hacker-types looking to find ways to unlock the phone so we can have more access into it. These days we have a fairly good grasp of the stuff that such phones might teach us about retail models, though there may still be people interested in buying that one off of you.