So it has been some time since I fulfilled my missing achievements!
SteemScan
In this website you can find at first sight the volume and latest price of Steem coin in a graph that's easy to understand. It is very user friendly and it makes it easier for you to exchange your Steem coins into BTC, TRX and USDT by having a quick convertor that you can use.
Behind this, there's a detail of every transaction and blocks that have been made!
As well as this, you can find at the top of the website a menu with different tabs, that provide you with more information:
By browsing this different tabs, you can find a lot of relevant information, such as the accounts that are witnesses and how active they are (if you feel like voting for them, you can do them right from SteemScan as well!). You can also look for different transactions that have been made into the chain, take a look at the apps that have been released or that are under development and who's the user in charge of them.
Quick Convertor
I have found this tool as the most useful one of all the website.
It allows you to trade your Steem coins into USD Tether, Bitcoin and Tron. You just have to fill in the withdrawal address and you can find the fees (there's a fixed rate for this) that will be charged to you detailed below.
This is my fulfillment for Achievement 5, task 2, proposed by @cryptokannon!