I have been using Google Forms as a logging app, creating a custom form, then saving a link to it on my phone's desktop, and then when I want to log my car's tire pressure or my cat's weight, for instance, I click the appropriate Form and fill in the values and they get added to a Google Sheet with a timestamp.
The ideal software would allow me to easily (without programming) create forms like Google Forms does, with options like radio buttons, checkboxes, explanatory text and images, numerical input fields (recognized by phone so it gives me a numerical keypad instead of a full keyboard), etc.
Basically the only differences from the actual Google Forms is that:
- they should not be publicly accessible, so other people can't find them and type stuff into them
- they should work without an internet connection, so more like a phone app that saves to the phone itself (and then syncs with a computer or cloud spreadsheet app when connection is established?) rather than a web page that saves to a server
Being able to fill out the form both on my computer and my phone is nice, but I guess not mandatory. It could be a pure phone app.