That's a handy site. I've been using the following two sites when judging how much fees to pay when making transactions. The first gives you an idea of how long various fees are taking to process, and the second gives you a nice graphical representation of how full the mempool is right now:

https://bitcoinfees.earn.com/ Edit: As pointed out below, this site overestimates required fees.

https://core.jochen-hoenicke.de/