Since led flat panel lights can be used to replace troffer fixtures, so led flat panel lights should be considered for every application where you would use a traditional fluorescent troffer.
Along with some other individual led lights, most lighting manufacturers are producing standard 1x4, 2x2, and 2x4 flat panels so that they can be used in drop ceilings. However, that is not the only application. These flat led ceiling lights can be mounted directly to a drywall ceiling. Since they can be as small as 1/2" thick, there is no need to recess them. It is possible to mount these to a wall, under a cabinet, or suspend them from the ceiling. Or, if you are replacing lighting in a drop-ceiling, flat panels work there too.
If you are looking for the led slim panel light, then you will need a model described as "Edge Lit". The other option would be "Direct Lit", and they typically have to be closer to 4" thick. Some of these models come with an option to add an emergency backup battery, so keep that in mind for your mounting location.
So, if your lighting project is for a room that is currently using troffers, consider new flat panel technology.