CryptoCurrency Exchanges
I created an account with Poloniex and Bittrex in 2016 but never used Bittrex up to this day.
Here's why:
I am always on mobile.

#Bittrex is NOT mobile-friendly. I couldn't find the selection of 190+ cryptocurrencies mentioned until I login and it is still difficult to navigate when logged in.

#Poloniex is MOBILE-FRIENDLY, the list of cryptocurrencies is in ALPHABETICAL ORDER and #Dogecoin is listed which makes it my favorite (I use DOGE to withdraw/transfer from exchanges because of low fee).
I created an account with Binance and Kucoin last year but haven't explored the latter.

#Binance is mobile-friendly and there is an app. I love it!
BUT... the list of cryptocurrencies is NOT in alphabetical order and Dogecoin is not listed to date. I don't like it.
Minimum trading amount and withdrawal fees are higher than Poloniex.
We CANNOT maximize "sell" amount not like Poloniex. 0.00999999 and below are always left on our Binance wallets. Do you like it? I don't! But, there are coins that are not available at Poloniex and available at Binance (i.e. #XVG, #EOS, etc.) vise versa so... "NO CHOICE". LOL!
I read that Poloniex has low reputation but for mobile user like me, it is still the BEST! I use it to buy/sell some altcoins except STEEM and SBD (@blocktrades is more CONVENIENT when buying Steem Power (SP) and cashing out STEEM and Steem Dollar (SBD) via #SteemConnect).
Others recommend #Changelly but see my mobile screenshot below:

Well, that's all for today folks!