Turn-by-turn navigation on imported routes for iphone

[Pinifarina]

Hi there!

I´m planning a motorcycle trip to the Alps so i´m looking for a gps software for my iphone 5s.
But the more i read, the more i get lost as each software has upsides and downsides.

So, can someone please help me on this?

I need a gps software for my iphone that:
- Allows offline navigation (maps on the iphone and using only internal gps antena)
- Allows to import tracks/routes pre-planned on my laptop
- That does not re-calculate the imported tracks/routes from laptop (very important - i want it drives me exactly through the course i planned on my laptop)
- Allows turn-by-turn navigation for imported tracks/routes
- If i get out of the course (by some reason), it can drive me back to the original course (to the point where i got out of the course or even to the nearer point of the original course).

Btw, a friend can borrows me a Garmin NUVI 2545 LM (Europe).
Does this device allows the above needs?

Anyone, please?

Thanks!