The Bancor Network offers a token swapping service called Bancor. Bancor is a simple DEX for trading Ethereum-based tokens.
Bancor is one of the highest liquidity DEXs. They provide a simple way to make modest buy/sell orders.
Bancor is a great way to accumulate a few ERC20s without a hassle. Try pairing Bancor with an Ethereum-based browser like the one found in Coinbase Wallet.
TIP: Bancor is geoblocking the US starting July 8th, 2019. Try Kyber as an alternative.