I was playing around with an app that tests my heart rate and it varies from 43 to approx 60. Usually in the mid 50s on average. This seems low to me? I'm not that fit, i run a few times a week. My BMI is about 23. I checked it during exercise and it seems normal then, around 150. Should I bring this up with the doc?
I also looked at the heart rate on my blood pressure reading (about a dozen) and they range from 49 to 60-something.
So first of all: what are you measuring with? Smart band/watch? Because they're all rubbish. The only semi-accurate consumer device is a chest belt pulsometer.
Not only is it more accurate, it measures way more often as well (e.g. every second). Smart bands activate every minute or so, which means it's almost impossible to get a proper max, since it lasts just for a few seconds.
Either could be the reason why your max is so low at 150.
As for the resting pulse: anything between 40 and 60 is considered good, if not textbook.
If you feel weak or sleepy during the day, or you wake up very tired, you should be diagnosed because of the symptoms, not because of the number on a pulsometer.
A cardiologist will probably prescribe you a holter. If you haven't used it yet, it's basically a pulsometer that actually works.

You carry it for at least 24h, sometimes for few days. You do as many different activities as possible and write everything down (what you did, how you felt, how well you slept).
The pulse-only kind is light and fuss-free.
You may also get one that measures blood pressure. That one is super irritating, but totally worth it. It's large and heavy, with an arm cuff that gets pumped every now and then.
