Looking for a simple and easy to use editor for generating and curating 2D object labels

Dear all,
I am looking for a simple to use label editor to curate 2D image labels.

Here is an example of the the type of data, where I need to edit the labels or generate them from scratch. This is a stack of PhC images with a stack of corresponding labels (these are bacteria in a micro-channel):

In this case, I generated the labels from a corresponding fluorescence channel. Some times these are over-/undersegment and I then need to edit some of them.
For other data I do not have corresponding Fluoresnce channel and I need to generate them from scratch.

I would be very grateful for suggestions for a simple editor that is able to handle this data, but does not to be super-featured.

Thanks and best regards,
Michael