I'm not sure this is the most appropriate place to post this so mods please feel free to move it if not.

I'm looking for a database app to run on either an iPhone or Android phone (my preference!) that I can sync with a desktop app.

I'm a small business (plumber) and I used to use a Psion (flat form database) to hold all my customers' details including the jobs I did for each of them. As times have moved on I thought it best to look at moving my data across to my smart(!)phone so I've been investigating mobile databases. My requirements are pretty simply; my customers (currently 2600) and their details and the many (so far 10 is most) jobs I do for each of them.

Can anyone make any reasonable suggestions as to a suitable tool/software?

I have discounted Handbase as it has no form function. Unfortunately, I don't think, cloud base stuff will work as I'm often without signal for up to two days.

Maybe there's an opportunity here! I have specced my needs out and they apply to very many one man band type businesses.