I was researching these small plug-in headphone amps recently and found several comments on forums about how bad they are generally. Several times I ran across folks that went with the $60 Zoom multieffects units. Long battery life, looping, nice stereo reverbs, etc.
https://www.sweetwater.com/store/detail/G1on
I was looking for something that I could plug my laptop in and play along with mp3s or Youtube videos, and this would do that very well. That might be something that you might wish to do later. Might be worth considering.