Apps similar to iTajPlus include MAPS.ME, which has a free version. Other options are Galileo Offline Maps and Karta GPS. In total there are three GPS Navigation Services like iTajPlus for iPad, iPhone and Android.
MAPS.ME offers the quickest offline maps of all the countries of the world. Travel with full confidence: wherever you are, MAPS.ME addresses all your offline mapping needs.
Russia
Probably the fastest maps ever on the App Store.
Galileo Offline Maps provides you with a collection of online maps: CloudMade good looking maps, MapQuest, OpenStreetMap, OpenCycleMap, OpenStreetBrowser, HikeBikeMap.
Caching is always on - Galileo saves map areas you have.
Poland
EU
Feature-packed offline navigation with turn-by-turn voice directions, enriched OSM maps, traffic-aware rerouting, lane assistance, restaurant details, parking finder, walking routes, contact navigation, arrival sharing, tourist guidance, and regular updates.
PortugalEU
