Binance Coin (BNB)
The Binance Coin is used exclusively on the Binance crypto exchange to facilitate cost-effective and efficient trading. The Binance exchange created and issued these coins. Users are able to pay exchange trading fees using this coin, rather than having a trade fee come out of the amount of the crypto being traded. If a user pays the trading fee with Binance Coin rather than as a cut of the traded crypto, the trading fee expense is cut in half during 2018 (discounts will decline in future years). Also, by paying fees in BNB, the user is able to avoid building up large amounts of dust in various wallets, because fractions of traded cryptos won't end up being left in various exchange wallets.
Mining/Staking
There does not appear to be any mining or staking of this coin. It appears that a set amount (approximately 200m) of BNB were issued (as ERC-20 tokens on the Ethereum platform), and Binance completely controls and distributed the initial supply.
Development Team
The team that built the Binance exchange also created this utility token.
Criticisms, Caveats, and Competitors
There isn't much to criticize. The Binance Coin is a logical way to lower trading fees if you use Binance. Other than that, the coin is not really useless outside of the exchange.
Additional Resources
The project's main website: N/A
Link to Wikipedia Page: N/A
Link to Reddit Community: https://www.reddit.com/r/BinanceExchange/ (for the exchange itself)
Link to Twitter account: N/A
Link to Team information: N/A
Link to data on Live Coin Watch: https://www.livecoinwatch.com/price/BinanceCoin-BNB
Whitepaper: N/A