Best Budget fitness tracker watch under £40?

anotherquestion

Hi folks, 
I have been looking at my partners budget Honor band 5 fitness tracker watch (due to her phone been reset and having to pair it up with the watch part again) and though in the past I wouldn't have thought of getting one of these watches I am beginning to like the idea.
I understand these kind of watches have various health related functions such as heart rate, sleep timer function, step counter, workout, workout timer, and will also vibrate when you get a phone call, and can be a handy phone finder as well.
I believe a lot of these functions work best when you have downloaded the Huawei app to the phone, which I did find a real pain to set up.
Another function that I like a lot is, you can download a lot of different watch faces to suit your mood.
So I am on the lookout for an under £40 fitness tracker watch with as many health functions as possible with the ability to install different watch faces GUI, which I really want.
Just wondering can I use any of the brands apps with each other or only the app for that watches brand?
Any suggestions gratefully appreciated, for under £40 but even better if in the £25-£30 bracket.
Oh I know I don't really need this but once I have experimented a little with one I just want to give myself a small treat.
Many thanks for any advice.

chrisw

Probably better looking at second hand for that price. Fitbit Charge 2 is around that price and works pretty well.

GDB2222

I use a Xiaomi Mi Band 4. It costs £20 and does all that you specified.

Murmansk

The Amazfit Bip is well reviewed, I've got one on Sale on Ebay but I'm probably not supposed to post a link. 
You can certainly choose from lots of free watch faces and its battery last for 30 or 30 days between charges.