Gathering/recap lists, giving an overview of unchecked items of other lists

[Polux49]

Hi! Thank you for this app. It is the only open source one that I found, still under development and feeding most of my needs. I'm missing one feature, though.

I have several lists L1, L2, L3..., each one corresponding to various sorts of products (shopping lists S1, S2, S3..., for frozen products, for vegetables, for cleaners...) or tasks (todo lists T1, T2, T3..., for tasks regarding my job, my family, my house...). When shopping, I navigate between lists, and I check items in the lists each time I find a product. But my lists can be long, and I have numerous ones. I can easily miss that some items are still unchecked, although the corresponding product is available in the shop.

Thus, I would appreciate that the app allows to gather all the unchecked items (and only them) of all my lists in a single recap list RL, so that whenever I check an item in RL coming from some list Lk (by clicking on it, either in RL or Lk), it is checked in Lk, and disappears from RL, simultaneously.

Optionally, but very preferably, one could have use of several recap lists, each one recapping unchecked items from some subset of lists. For example, a recap list RS for lists S1, S2, S3..., and another recap list RT for lists T1, T2, T3..., would allow to recap separately the unchecked items from shopping lists on one hand, from todo lists on the other hand.