I like to track the places that I have been to. Some people have a scratch world map, others write a list, or draw onto a map. For me I realized that the granularity of a world map is not enough, I want to have a digital map. So for a while I have been using the Viking application for this.
There I can just create layers and enter the points as I see fit. It works rather nice, but it became rather slow lately. Additionally I cannot take this with me on the phone. On the go I can add places in OsmAnd and later export them and import them into Viking. All this is okay, but I wanted to see what Google offers there.
Google Maps offers to store places in lists. One can create many lists and just add places there. These are then shown on the map. This is nice, because it gives about the same overview that I have with my thing in Viking.
But there are two big caveats: One cannot export these. I have tried, and it does not work even when exporting all the data from Google Maps. This might be something that one can sue for with the GDPR, but I won't bother with that. The other caveat is that there is a limited number of places that can go into these lists and then it will just remove the oldest elements. I might exceed the limit without even realizing it, losing data. Also I found that these points are not always shown on the map when one pans and zooms.
The other option are custom maps. These are really nice as one can add as many layers as one wants. And then add points in there, give them custom labels. One can also display the label on the map such that it gives the same user experience as I have with Viking.
Google Maps already knows about a lot of places, therefore it is easier to find places and add them to the map. The problem here is that one cannot edit them on Android. It seems to be something that one edits on the computer. Therefore I would need to do something else to add the points on the mobile anyway and transfer them into my custom map. In the end this does not give me much advantage over my current setup.
Both Viking and the personal maps on Google Maps support the import and export of the places as KML files. One can simply move between the two at will.