When comparing MAPS.ME vs FairEmail, the Slant community recommends FairEmail for most people. In the question“What are the best Android apps?” FairEmail is ranked 7th while MAPS.ME is ranked 11th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Very detailed selection of areas to download
That saves a lot of download, e.g. from ~500MB in other applications it is reduced to ~50MB for German surroundings.

Pro Includes offline routing and turn-by-turn navigation
Users without a data connection can still use the app for turn by turn directions, which is great for those that travel or use a device that does not have a cellular data connection.
Pro Obtains data from community-based OpenStreetMap
MAPS.ME uses data from OpenStreetMap, meaning the data retrieved from that service is a community-based map. Anyone can freely edit and contribute to the map, a map concept that is similar to Wikipedia.
Pro Fast rendering
By using compression of the map data, MAPS.ME is able to speed up the rendering of their maps to one's device. This allows for a quicker feeling app.
Pro Optionally can download traffic information
And showing it color-coded (Google-maps-like) on the streets.
Pro Discover nearby feature
Shows a nicely organize list of interesting places to visit close to your current location.

Pro Matching modern material-like interface
The design of the app uses a material-like interface making for a close to native looking experience on Android.
Pro Offline vector maps
Automatically downloads vector maps for offline use.
Pro No nagging advertisements
Pro Easy to install
Pro Easy adding/editing of bookmarks/favorite places
Click on the map and you will have the option to Bookmark, Route From, Route To. Having selected Bookmark simply offers to edit it, e.g. give it a different name.
Pro Allows to edit OpenStreetMap data
It is possible to add new and edit existing POIs in OpenStreetMap database using a nice interface.
Pro Night mode
There is a night mode option.
Pro Integration with booking.com
Displays information from booking.com about hotels and apartments.
Pro Open source
Pro Multiple account support
Multiple identities per account, notifications per account or contact.
Pro Actively maintained
It is actively maintained. The used libraries are up to date and bugs are fixed quickly.
Pro Privacy-Focused
There are no trackers within the app and trackers sent with mails are disabled by default. This app lets you read and compose emails with your privacy in your very own hands.
Pro Fast and customizable
Privacy features are excellent.
Pro Lightweight
~ 20 MB.
Pro Identities support
Pro Two way synchronization
Pro Flat conversation threading
Pro Encryption support
Supports both OpenPGP and S/MIME encryption for total privacy.
Pro Support for safety and low-bandwidth
Allows to configure maximum size of email downloaded immediately.
Pro Can show plain text of html mails
Pro Show links before opening
Some HTML mails may show different links and link texts, this app however will show you the real link before opening, protecting against phishing and scams
Pro Recognize spoofing internationalized domain names
Some domain names may use non-ASCII characters looking similar to the latin alphabet (e.g. some cyrillic characters). This app will show you the punycode representation of the domain, if that is the case and thus protect you against phishing and scams.
Pro Reformat the HTML mail for increased privacy
Some HTML mails may include ressources that can track you. This app doesn't load them by default, but reformats the text, increasing both privacy and readability.
Pro Autoconfiguration with open standards
There are open standards for any email provider to show how an email client should connect to the server. This app supports both RFC 6186 as well as Thunderbird Autoconfiguration standards.
Pro OAuth support for most common mail providers
Supports authenticating with the mail server using OAuth, thus increasing security.
Pro Low RAM usage at the right setings
Cons
Con Poor response time to recalculate the route
Con No option for satellite/aerial/topographic imagery
Not as useful for navigating while hiking/climbing/etc.
Con Very slow search and route calculation
Probably because MAPS.ME has more POIs in its database which ends up with all searches and route calculations being very slow.
Con No display of speed limit
Neither the next nor the current one.
Con No way to distinguish between fastest, efficient or shortest route
Con Very limited options
E.g. no way to hide certain buttons like the traffic button, or to configure the language used to display city names.
Con Sometimes very strange suggestions
E.g. when not using the suggested route, Maps&Me continues to request to turn even if you are more than 100m after the cross-road.
Con Favorites are a little bit too hidden
Because they are stored in groups.
Con Traffic information is not available in all countries and cities
Source of traffic info is a trade secret this feature is only available to some selected cities.
Con No lane assist
Con Being based on OpenStreetMap data can be lacking
The use of OSM also has the drawback of many places not getting the attention needed for updates. Depending on the geographic location OSM may have the most detailed maps or the most bare/outdated map.
Con Does not show images offline
Does not show images offline if supplied in standard kmz file. i.e. zipped kml plus image folder.
Con No tourist detail maps
Con No Microsoft exchange server support
Con UI might be a bit confusing for some
