Best way to share data across devices?

[apm17]

Friends --

I'm a newbie here. My wife and I had been sharing fuel data via a shared xls file. Now we're trying Fuelly / Gas Cubby. We want to be able to each enter data separately, and be able to sync and see that data on whichever device we're using -- 2 iPhones, and also access via laptop from time to time.

On other types of apps (shopping, packing lists, etc.), we each have a separate account i.e. *2 different user logins*, and we give each other access so we can share data. We have 2 accounts, but the relevant data syncs between us. I can't see how to do that here.

We could use *1 account* and just share the login info so we both login to this app using that one account. Is that the way to do it here?

Thanks,
Alex