I take my BP once a month. I have printed a grid of squares on which I write my readings. Ahead of my annual medication review I email my chart to the surgery. I also have a small pocket diary in which I record any health-related details and appointments to take along to any hospital or GP visits. A lot of apps are far more complicated than I can be bothered with. For my daily steps I still use an old fashioned 3D pocket pedometer - so much easier to see at a glance.
DH simply uses a word table. Tried to get him to use excel as you could then put sums in to monitor changes but he is happy with the table, which he sends in
I used BP Journal. It's free and easy to use. It gives you a rolling 30 day average, statistics and charts which are customisable, for example, you can choose to look at results from a certain time period. It allows your data to be explored to pdf files which can be sent to your GP.
I use the app that comes free with my Omron BP device - syncs my weighing scales too. Bit of a faff to set up but once done it keeps the records for years. I used to be 8 stone apparently (didn't have the Bp machine at that time) - thanks Omron
I use HealthNest app. It’s really easy to use and will record all your readings and keep a running average of the last week or month’s worth of recordings. Designed by a GP and very simple.
For our GP surgery, you're supposed to be able to send BP figures online, but I can't make it work so I just take a photo and send that. I know it makes a bit more work for the staff.
My home monitor has a memory that records the last 30 or so. If I can be bothered, I later copy them out. The trouble is, my DH uses the machine too, so we don't know whose is whose! Well, we do actually, because his result is always in his boots.