We did that for #TronNetwork and aggregated all the prices from all the DEXes on #Tron within our mobile dApp (Android).
Well is not the greatest idea as now the exchanges are using Smart Routers and a smart router finds the best path to the best price and some of them also uses other DEXes liquidity like @JustMoney uses sun.io liquidity. Meaning your direct route could cost the user less tokens in its balance. We are looking now to use the liquidity over all the DEXes and create our internal pathfinder so that we get the user the best price.
If you want to check more our DEX Aggregator