Anything else to try? Yes, put it outdoors.

Variety name? Age/size of plant now? Were these blooms on when bought or are they new since purchase? Have you transplanted it or just left it in the same container? Have you fed it if so with what? Over-watered? Does it get enough sun? Air temps indoors? Do you know how blossom drop works and its causes?

Lots of questions that need answers especially since you are trying to grow this and get it to set fruit indoors. That isn't at all its normal growing environment. It needs to be outdoors.

Since you have tried all those things and it still won't set fruit then there is something else wrong with the plant.

Dave

It's a cherry tomato that's near the window of a glassed in terrace that gets plenty of sun. It was transplanted a few weeks ago, and has a had very light amount of fertilizer with each watering after it had a chance to acclimate after transplanting. Don't know the variety, but it's compact and I thought it could grow indoors.

I thought a flower means you could have a tomato if you got the pollen in the right place. Maybe one of those setting sprays? Do they work? We were successful in growing hot peppers indoors before the aphids got them.

There are several reasons why a flower will not become a tomato. That means there are several requirements that must be met to get fruit.

Here is a link that might be useful: Blossom Drop

I thought a flower means you could have a tomato if you got the pollen in the right place.

Sorry but it isn't that simple. Wouldn't we all love it if it was. :)

Even under ideal conditions, which doesn't include growing indoors, only a percentage of tomato blooms will set fruit. How high that percentage is depends on many different factors including all the ones I listed above - variety, light spectrum, available hours of sun, air temperatures, humidity, air circulation, nutrients, water, soil, container size if in one, etc.

Sun through a window isn't nearly as intense as sun outdoors, air circulation is minimal if any, if you have air conditioning the temps may well be too cool at night, if no A/C then it may well be too hot for viable pollen, too much N fertilizer means no blooms/fruit set, etc.

A tomato can be grown indoors in a greenhouse with extra work but otherwise it needs to be outside for best results.

Dave