Thank you.

Your list is very useful for beginners.

I would add:

https://jochen-hoenicke.de/queue/#24h - check the necessary fee to make BTC transaction
https://ethgasstation.info - check the necessary gas to make ETH/token transaction

I'll be happy if somebody add sites about network status or something else like that. Thanks for it!

Do you know sites where I can find more followers to my twitter?

I'm not good in IMarketing but if you make hashtags(#Followback#crypto #bitcoin, #following, #followme) then probably you will get them.