edit: Thanks for the responses. It was the toast notifications coming from these 2 addons.
Screenshot 1:
http://imgur.com/BfBeIfx
Screenshot 2:
http://imgur.com/dvhfz31
The addon I'm looking to be identified is the one shown in the bottom right of the screen in those screenshots.
List of everything enabled:
_NPCScan
_NPCScan.Overlay
Altoholic
Altoholic_Achievements
Altoholic_Agenda
Altoholic_Characters
Altoholic_Grids
Altoholic_Guild
Altoholic_Search
Altoholic_Summary
Archy
AtlasLoot
AtlasLoot_BurningCrusade
AtlasLoot_Cataclysm
AtlasLoot_ClassicWoW
AtlasLoot_Crafting
AtlasLoot_Loader
AtlasLoot_MistsofPandaria
AtlasLoot_WorldEvents
AtlasLoot_WrathoftheLichKing
Auc-Advanced
Auc-Filter-Basic
Auc-ScanData
Auc-Stat-Histogram
Auc-Stat-iLevel
Auc-Stat-Purchased
Auc-Stat-Simple
Auc-Stat-StdDev
Auc-Util-FixAH
BeanCounter
DataStore
DataStore_Achievements
DataStore_Agenda
DataStore_Auctions
DataStore_Characters
DataStore_Containers
DataStore_Crafts
DataStore_Currencies
DataStore_Inventory
DataStore_Mails
DataStore_Pets
DataStore_Quests
DataStore_Reputations
DataStore_Spells
DataStore_Stats
DataStore_Talents
Enchantrix
Enchantrix-Barker
Grail
Grail-Achievements
Grail-Reputations
Grail-When
Informant
Loremaster
MBB
MogIt
MogIt_Accessories
MogIt_Cloth
MogIt_Leather
MogIt_Mail
MogIt_OneHanded
MogIt_Other
MogIt_Plate
MogIt_Ranged
MogIt_TwoHanded
Overachiever
Overachiever_Tabs
Overachiever_Trade
PetTracker
PetTracker_Breeds
PetTracker_Config
PetTracker_Journal
PetTracker_Switcher
PetTracker_Upgrades
Profession_Assistance
Skada
SlideBar
Spy
Stubby
!Swatter
ElvUI_Config
ElvUI
DBM-StatusBarTimers
DBM-Core
DBM-DefaultSkin
DBM-GUI
DBM-BaradinHold
DBM-BastionTwilight
DBM-BlackTemple
DBM-BlackwingDescent
DBM-BWL
DBM-Brawlers
DBM-ChamberOfAspects
DBM-Coliseum
DBM-DMF
DBM-DragonSoul
DBM-EyeOfEternity
DBM-Firelands
DBM-HeartofFear
DBM-Icecrown
DBM-Karazhan
DBM-MogushanVaults
DBM-MC
DBM-Hyjal
DBM-Naxx
DBM-Onyxia
DBM-Outlands
DBM-Pandaria
DBM-Party-BC
DBM-Party-Cataclysm
DBM-Party-MoP
DBM-Party-WotLK
DBM-AQ20
DBM-Scenario-MoP
DBM-Serpentshrine
DBM-SiegeOfOrgrimmar
DBM-Sunwell
DBM-AQ40
DBM-TerraceofEndlessSpring
DBM-TheEye
DBM-ThroneFourWinds
DBM-ThroneofThunder
DBM-Ulduar
DBM-VoA
DBM-WorldEvents