How to View Another Player's Tier In-Game
The main point of TierTagger is seeing tiers without alt-tabbing to a website. Once the mod is installed and configured, tiers appear next to player names in the places the mod hooks into, so you can read someone's tier straight from chat, the tab list, or their nametag.
Where Tiers Show Up
Look for the tier prefix attached to the player's name. The mod renders tags like HT1, LT1, HT2, LT2, and so on down through the lower tiers. When you see a player in the tab list or in chat, the tag should sit right beside their name. Hovering or reading the nametag above their head is another place the tag can appear depending on your settings.
If a Player Shows No Tier
A missing tag usually means one of a few things: the player is not listed on the tierlist you have selected, they are listed under a different gamemode than the one you are viewing, or the mod has not refreshed its data yet. Switch gamemodes in the config to check their other tiers, and let the mod auto-update so newly ranked players appear.
Remember the tag reflects the tierlist's data, not live skill, so an unranked player simply has no entry to display.