I use Steptracker. It's free, but you do get the occasional advert. It does come with GPS tracker, so you can monitor those long walks as well.
Samsung health from the play store, sets you a target of 200,000 steps per month & links you to every other user world wide, I'm usually in the top 5% for my age group & average around 290000 to 300000 steps per month. There are other features such as weight, blood pressure & sleep monitor. Edit: No adds & it's free
Recent walking I have been taking the golf umbrella in case it rains. As you do you end up using it as a walking stick. When I don’t take it I have started missing it so I purchased a pair of them trekking sticks with the idea of just using one. After researching which to get I dropped on all this Nordic Walking stuff. Seems like it’s very close to swimming for exercise. Has anybody tried it?
I use a Suunto GPS watch for recording walks which is supported with an app on my phone. The problem with phone apps is that on long multi-day walks they use far too much power and deplete your battery. If you're also using a mapping map on your phone (I use OS Maps) this could mean you get into a navigational pickle.
It depends what you want from it, I use Strava for both walking and cycling. I don't pay so it only tells me my average speed rather than current speed which I think is a bit stupid. It doesn't tell me anything like heart rate etc, you need a wearable device for that. It does track your walk and shows you distance and height gained/lost etc.
Huawei watch sinks to my Honor (Huawei) phone and uses the Huawei Health App. No idea of my stats but the Chinese Govt could probably tell you
Once went on a men's health day. Different activities. One was a few mile walk using the sticks. Was suprised to be informed that by using them increases calorie burning by 30%.
Strava - Been using it for cycling & walking for 6 years now great app. Steps App - Logs your daily steps and puts it in a calendar style format so its easy to compare steps per month etc