Here is something i just posted on tripadvisor discussing maps.me:
Maps.me is also free. It is open source.
Maps.me takes up less memory and provides all available details in a single map file. For example if i download the Vancouver Map, which is a single complete file, it includes everything in southwestern BC including well past north of Whistler and east to almost but not including Kelowna and only takes up about 50 MB. Maps.me gives you a lot of details on restaurants hotels shopping etc. and nothing is missing depending on how much you zoomed when you download (see below for comparison with google)
With Googles Map if you approximate the same area as maps.me for download, it will take almost 150 MB, which is 3 times as much memory. Another thing is if you down load a wide area some of the details are lost in the downloaded map compared to when you zoom in on a tighter area bfore downloading. For example if you make a download of southwestern bc and then download just downtown Vancouver and compare the two offline maps of the block where the Fairmont Hotel Vancouver is located, there is a big difference in the details and the number of shops and restaurants.
I would rather not have to download a wide map and then a bunch of zoomed in maps under google and switch back and forth. With maps.me there is a single map file. The details are not as great as with a zoomed in google map, but i have found the details to be pretty darn good. Certainly, major attractions, hotes, restaurants and shops are there. Also, a nice feature is that the address numbers are shown in maps.me.
Like i said if i have wifi i will use google directly. But offline, i prefer maps.me.
Edit: PS i only use a digital map if i am truly lost. I am afraid of dropping or losing my tablet. I usually get by fine with a free hotel tourist map.