When comparing ZANavi vs Sygic, the Slant community recommends Sygic for most people. In the question“What are the best GPS navigation apps for Android?” Sygic is ranked 3rd while ZANavi is ranked 13th.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Anyone can use or share the code
It's licensed under GPL which make sit ope-source, where anyone can look at or use the code which allows for an open understanding of the app.
Pro Usability focused
The core of the app is designed around ease of use which makes it an intuitive app to use.
Pro Heads up display
Pro Offline navigation
Internet connection is not required.
Pro Lane guidance
Pro Detailed and up to date commercial map data
Utilizes commercial data for its maps. While not strictly better it can have more up-to-date map data than OSM with better coverage. This is also the reason for the the good address data.
Pro Good address data
This app can locate address without external data.
Cons
Con Limited maps
There are many missing maps from the database making for user limitation depending on the are one lives.
Con Updates require running the app
After a Play Store update it is important to run the app once to download all the offline data again, otherwise it will not be usable when no external data is available.
Con Poor map viewing
Sygic's interface is tailored to navigation. While viewing maps in 2D is possible, it populates the map with a bunch of POI icons which detract from street names. The biggest issue is how easy it is to select something or start navigation when zooming in/out.