CalcKey just rebranded to Firefish. It has a very pretty UI but UX is currently bad as there is no way to globally disable boosts so you will see the same posts in your timeline over and over and over again. Following hashtags is limited to the Antennas feature so you won't see those posts in your timeline. Until they fix these things it's unusable for me personally.
Have you tried Akkoma or Pleroma? I run an Akkoma instance at https://shrediverse.net if you want to try it out. You can use the web app or an app like Fedilab on Android.