A few trips ago I painstakingly built some custom maps on Google with places we wanted to visit, but I could not get back to it on my phone, so that time was wasted. Right now the best solution I have is to save favourites on Trip Advisor, but that's still not great. Any tips or apps that you've used that can help me build something like that?
I love using HERE We Go maps for that purpose. I download the map for the country/state/région whatever that I am going to visit, then build a collection for each specific city or area I am going to (and of course I start by entering my hotel first !)
Then when I am on site, I don't need data to use the map function and get to any of my sites !
My suggestion would be to use Google Maps since there's nothing better. I know you said you had trouble, but a little practice first goes a long way.
Website: "Saved" flag on the left > Maps tab
Phone App (Android, no idea for iPhone): "Saved" flag at the bottom > scroll to the bottom and tap Maps
For iPhone (pretty much the same): https://support.google.com/maps/answer/3045850?hl=en&co=GENIE.Platform%3DiOS
Do a couple test runs before you put much work into it. You'll get it.
I use all Apple devices, so my answer is based on that. You might want to try checking your Google Maps settings on your phone. For my iPhone, I have “Background App Refresh” and “Cellular Data” turned on. That might help your maps synch on both your computer and phone. Other folks may have ideas on things to check regarding your phone and app settings.
Have a look at Sygic Travel Maps.
I use Sygic GPS navigation and it is a really good app; especially the offline capability because it uses pre-downloaded country maps; so no need for connection during travel.