Update September 2021
Since publishing this original article, defi has made great strides towards decentralization. Now, virtually all uniswap data consumers use The Graph to interface to function in a better indexed and distributed manner.
1. BZX
“bZx is currently using uniswap as a price oracle.”:
2. DefiRate
An interest rate comparison tool, seems to use them
3. Others
UniSwap Ninja: https://www.reddit.com/r/UniSwap/comments/d0hjwc/uniswapninja_decentralized_token_listing_and/
BlockLytics: is offering it for their clients: https://blocklytics.org/blog/uniswap-api/
Debank: https://debank.com/projects/uniswap?mode=data Shows volume price liquidity. You can tell possible good pumps before they happen by looking at liquidity as a ratio of market cap.
AAVE: https://app.aave.com/home
Now, aave lending protocol, lets you leverage those pool tokens for more pool tokens. If you keep leveraging you can more than double your pool tokens, while getting rewards from providing liquidity.
It is bonkers. They are about to integrate set tokens(tokenized swing/algo strategies) next. Imagine leveraging an ETH swing trading token
(Note this is in beta, not yet on mainnet as of 5/29/2020)