What is the MOST Underrated app/package?

Just like the tittle says, what is an app/package that is amazing but seriously under rated?

I bought a unit thats arriving soon and I wanted to get peoples thoughts on what and why packages they think are really cool that may not be the most popular.

Also just any general input, tips info, suggestions. This is my first Dappnode product… I have experience with another Blockchain CPU product, but thought it was time to give this one a try so feel free to leave your 2 satoshis, any insight is appreciated.